Transition metal compound as catalyst component for polymerization, aromatic vinyl compound-olefin copolymer having stereoregularity and method for its preparation by means of the transition metal compound as catalyst component

ABSTRACT

A transition metal compound of the following formula (1) as catalyst component for the production of an aromatic vinyl compound polymer or an aromatic vinyl compound-olefin copolymer:                    
     wherein A is a specified unsubstituted or substituted benzindenyl group, and B, M, Y, and X are as specified.

This application is a continuation in part of U.S. patent applicationSer. No. 09/048,000 filed Mar. 26, 1998, now U.S. Pat. No. 6,235,855 andincorporated entirely herein by reference.

The present invention relates to a transition metal compound as catalystcomponent for polymerization, a method for producing an aromatic vinylcompound type polymer employing it, a method for producing an aromaticvinyl compound polymer and an aromatic vinyl compound-olefin copolymer,having an isotactic stereoregularity, and a novel aromatic vinylcompound-olefin copolymer.

Also, the present invention provides a non-crystalline aromatic vinylcompound-ethylene random copolymer having a high random property (lowalternating property) of novel structure, having an isotacticstereoregularity and having a feature that even after sufficientlysubjecting to crystallization, a crystallinity derived from an aromaticvinyl compound-ethylene alternating structure is not observed. Further,the present invention provides a novel transition metal compound for ascatalyst component for polymerization.

For the production of a copolymer of an olefin with an aromatic vinylcompound, such as ethylene with styrene, studies have been conductedprimarily by using so-called heterogeneous Ziegler-Natta catalysts (e.g.Polymer Bulletin, 20, 237-241 (1988), Macromolecules, 24, 5476 (1991)).However, conventional heterogeneous Ziegler-Natta catalyst systems arenot so practical, since the catalytic activities are low, the styrenecontent in the product is very low at a level of a 1 mol %, or theproduct does not have a uniform regular copolymer structure or containsa substantial amount of homopolymers such as polyethylene and isotacticor atactic polystyrene.

Further, the stereoregularity of the obtained polystyrene is isotactic,but in the copolymerization, no stereoregularity of an alternatingstructure of styrene and an olefin is observed, or an alternatingstructure itself is not substantially contained.

Further, some styrene-ethylene copolymers obtainable by using so-calledsingle-site catalyst systems comprising a transition metal compound andan organoaluminum compound, and methods for their production, have beenknown.

JP-A-3-163088 and JP-A-7-53618 disclose styrene-ethylene copolymerswhere no normal styrene chain is present i.e. so-called pseudo randomcopolymers, obtained by using a complex having a so-called constrainedgeometrical structure. Here, a normal styrene chain is meant for ahead-to-tail bond chain. Further, hereinafter styrene may sometimes berepresented by St.

However, phenyl groups in the alternating structure of styrene-ethylenepresent in such pseudo random copolymers, have no stereoregularity.Further, no normal styrene chain is present, whereby the content ofstyrene can not exceed 50 mol %. Further, the catalytic activities arepractically inadequate.

JP-A-6-49132 and Polymer Preprints, Japan, 42, 2292 (1993) disclosemethods for producing similar styrene-ethylene copolymers wherein nonormal St chain is present, i.e. so-called pseudo random copolymers, byusing a catalyst comprising a bridged metallocene type Zr complex and acocatalyst.

However, according to Polymer Preprints, Japan, 42, 2292 (1993), phenylgroups in the alternating structure of styrene-ethylene present in suchpseudo random copolymers, have no substantial stereoregularity. Further,like in the case of a complex having a constrained geometricalstructure, no normal styrene chain is present, and the styrene contentcan not exceed 50 mol %. The catalytic activities are also practicallyinadequate.

Further, it has recently been reported to produce a styrene-ethylenecopolymer close to an alternating copolymer having a stereoregularityunder a condition of an extremely low temperature (−25° C.) by using1,2-ethylene(—CH₂—CH₂—) bridged bisindenyl type Zr complex;rac[ethylenebis(indenyl)zirconium dichloride] (Macromol. Chem., RapidCommun., 17, 745 (1996)).

However, from the 13C-NMR spectrum disclosed, it is evident that thiscopolymer has no normal styrene chain. Further, if copolymerization iscarried out at a polymerization temperature of at least room temperatureby using this complex, only a copolymer having a low styrene content anda low molecular weight is obtainable.

On the other hand, a styrene-ethylene alternating copolymer obtainableby using a Ti complex having a substituted phenol type ligand, is known(JP-A-3-250007 and Stud. Surf. Sci. Catal., 517 (1990)). This copolymerhas a feature that it consists essentially of an alternating structureof ethylene and styrene and contains substantially no other structuresuch as an ethylene chain, a structure comprising an ethylene chain andstyrene or a structure of e.g. a head-to-head or tail-to-tail bond(hereinafter referred to as a heterogeneous bond) of styrene. Thealternating index (value λ in the present specification) of thecopolymer is at least 70, substantially at least 90.

Namely, the resulting copolymer is a copolymer having a very high degreeof alteration and consisting substantially solely of the alternatingstructure, whereby it is substantially difficult to change thecompositional ratio of the copolymer consisting of 50 mol % of ethyleneand 50 mol % of styrene. Further, the stereoregularity of phenyl groupsis isotactic, but the isotactic diad index m is about 0.92, whereby themelting point is low at a level of from 110 to 120° C.

Further, the weight average molecular weight is low at a level of20,000, which is inadequate to provide practically useful physicalproperties as a crystalline polymer. It should also be added that thecatalytic activities are very low, and the copolymer can hardly beregarded as practically useful, since it is obtained as a mixture withe.g. syndiotactic polystyrene.

It has been attempted to produce a copolymer of a propylene with styreneby means of a Solvay type Ziegler-Natta catalyst (Macromolecules, 22,2875 (1989)). However, the catalytic activities are low, and the styrenecontent is at a level of 4.4 mol % at best. With respect to asingle-site catalyst system comprising a transition metal compound andan organoaluminum compound, a case wherein a Ewen-type zirconium complexwhich is a so-called metallocene catalyst, is employed forcopolymerization of propylene with styrene, is known (JP-A-8-269134).However, the styrene content of the copolymer thereby obtainable is aslow as a few %, and the stereoregularity is syndiotactic.

The production of an isotactic aromatic vinyl compound polymer such asan isotactic polystyrene, has been studied by means of a so-calledheterogeneous Ziegler-Natta catalyst.

For example, such a catalyst is disclosed in Macromolecules, 24, 5476(1991), but the catalytic activities are low, and as a fate of aheterogeneous Ziegler-Natta catalyst, due to non-uniform active sites,the molecular weight distribution (Mw/Mn) tends to be as broad as atleast 3, and cation polymerization and other polymerizations tend tosimultaneously proceed, and a substantially a large amount of atacticpolystyrene is usually produced as a by-product.

On the other hand, in the polymerization of styrene using a single-sitecatalyst, syndiotactic polystyrene is usually obtained. Only when anickel-type non-metallocene complex is used, formation of isotacticpolystyrene has been reported, for example, in Macromolecules, 29, 4172(1996). However, the molecular weight, the catalytic activities and thestereoregularities are all inadequate.

In any case, no isotactic polystyrene has been obtained with a systemusing a metallocene complex as a catalyst component.

It is an object of the present invention to provide a metal compound forpolymerization, a method for producing an aromatic vinyl compound typestereoregular polymer by using it, a method for producing an aromaticvinyl compound polymer and an aromatic vinyl compound-olefin copolymer,having isotactic stereoregularity, and a novel aromatic vinylcompound-olefin copolymer.

It is another object of the present invention to provide an aromaticvinyl compound-ethylene random copolymer having a high random property(low alternating property) and having substantially no crystallinityderived from alternating structure.

Firstly, the present invention provides a transition metal compound ofthe following formula (1) as catalyst component for the production of anaromatic vinyl compound polymer or an aromatic vinyl compound-olefincopolymer:

wherein A is an unsubstituted or substituted benzindenyl group of thefollowing formula K-2, K-3 or K-4:

wherein each of R1 to R3 is hydrogen, a C₁₋₂₀ alkyl group, a C₆₋₁₀ arylgroup, a C₇₋₂₀ alkylaryl group, a halogen atom, OSiR₃, SiR₃, or PR₂(wherein each R is a C₁₋₁₀ hydrocarbon group), provided that theplurality of R1, the plurality of R2 and the plurality of R3 may be thesame or different, respectively, and each pair of adjacent R1, adjacentR2 and adjacent R3 may together, with the atoms joining them, form a 5-to 8-member aromatic or aliphatic ring,

In the formulas K-2 and K-4, when each pair of adjacent RI and adjacentR3 form a 6-member ring together with carbon atoms, i.e. acyclopentaphenanthryl group, it is a substituted cyclopentaphenanthrylgroup expressed by the formula J-1 or J-2;

(In the above formulas J-1 and J-2, each of R11 and R22 is hydrogen, aC₁₋₂₀ alkyl group, a C₆₋₁₀ aryl group, a C₇₋₂₀ alkylaryl group, ahalogen atom, OSiR₃, SiR₃ or PR₂ (wherein each R is a C₁₋₁₀ hydrocarbongroup), provided that the plurality of R11 and the plurality of R22 maybe the same or different, respectively, and each pair of adjacent R11and adjacent R22 may, together with the atoms joining them, form one ormore 5- to 8-membered aromatic or aliphatic ring, except for a case thatall of the substituents are hydrogen.)

B is an unsubstituted or substituted cyclopentaphenanthryl group, or anunsubstituted or substituted benzindenyl group of the same chemicalformula as A, or an unsubstituted or substituted cyclopentadienyl group,an unsubstituted or substituted indenyl group or an unsubstituted orsubstituted fluorenyl group, of the following formula K-5, K-6 or K-7;

wherein each of R4 to R6 is hydrogen, a C₁₋₂₀ alkyl group, a C₆₋₁₀ arylgroup, a C₇₋₂₀ alkylaryl group, a halogen atom, OSiR₃, SiR₃ or PR₂,(wherein each R is a C₁₋₁₀ hydrocarbon group), provided that theplurality of R4, the plurality of R5 and the plurality of R6 may be thesame or different, respectively,

when both A and B are unsubstituted or substituted benzindenyl groups,they may be the same or different,

Y is a methylene group or a silylene group, which has bonds to A and Band which has, as substituents, hydrogen or a C₁₋₁₅ hydrocarbon group,wherein the substituents may be the same or different from each other,or Y may have, together with the substituents, a cyclic structure,

X is hydrogen, a halogen atom, an alkyl group, an aryl group, analkylaryl group, a silyl group, a methoxy group, an ethoxy group, analkoxy group or a dialkylamide group, and

M is zirconium, hafnium or titanium.

The unsubstituted benzindenyl group may, for example, be4,5-benz-1-indenyl (another name: benz(e)indenyl), 5,6-benz-1-indenyl,or 6,7-benz-1-indenyl, and the substituted benzindenyl group may, forexample, be 4,5-naphtho-1-indenyl, 4,5-pyrene-1-indenyl,4,5-triphenylene-1-indenyl, a-acenaphtho-1-indenyl,3-cyclopenta[c]phenanthryl or 1-cyclopenta[1]phenanthryl.

Particularly preferably, the unsubstituted benzindenyl may, for example,4,5-benz-1-indenyl (another name: benz(e)indenyl), 5,6-benz-1-indenyl,or 6,7-benz-1-indenyl, and the substituted benzindenyl group may, forexample, be α-acenaphtho-1-indenyl, 3-cyclopenta[c]phenanthryl, or1-cyclopenta[1]phenanthryl.

In the above formula (1), B is preferably the same unsubstituted orsubstituted benzindenyl group as above A, or an unsubstituted orsubstituted cyclopentadienyl group, an unsubstituted or substitutedindenyl group or an unsubstituted or substituted fluorenyl group, of thefollowing formula K-5, K-6 or K-7:

In the above K-5 to K-7, each of R4, R5 and R6 is hydrogen, a C₁₋₂₀alkyl group, a C₆₋₁₀ aryl group, a C₇₋₂₀ alkylaryl group, a halogenatom, OSiR₃, SiR₃ or PR₂ (wherein each R is a C₁₋₁₀ hydrocarbon group),the plurality of R4, the plurality of R5 and the plurality of R6 may bethe same or different, respectively. However, B is preferably in aracemic-form (or pseudo racemic-form) with A.

Particularly preferably, B is, as an unsubstituted benzindenyl group,4,5-benz-1-indenyl, 5,6-benz-1-indenyl or 6,7-benz-1-indenyl, or as asubstituted benzindenyl group, α-acenaphtho-1-indenyl,3-cyclopenta[c]phenanthryl, or 1-cyclopenta[1]phenanthryl, or as anunsubstituted indenyl group, 1-indenyl, or as a substituted indenylgroup, 4-phenylindenyl or 4-naphthylindenyl.

The unsubstituted cyclopentadienyl may, for example, becyclopentadienyl, and the substituted cyclopentadienyl may, for example,4-aryl-1-cyclopentadienyl, 4,5-diaryl-1-cyclopentadienyl,5-alkyl-4-aryl-1-cyclopentadienyl, 4-alkyl-5-aryl-1-cyclopentadienyl,4,5-dialkyl-1-cyclopentadienyl,5-trialkylsilyl-4-alkyl-1-cyclopentadienyl, or4,5-dialkylsilyl-1-cyclopentadienyl.

The unsubstituted indenyl group may, for example, be 1-indenyl, and thesubstituted indenyl group may, for example, be 4-alkyl-1-indenyl,4-aryl-1-indenyl, 4,5-dialkyl-1-indenyl, 4,6-dialkyl-1-indenyl,5,6-dialkyl-1-indenyl, 4,5-diaryl-1-indenyl, 5-aryl-1-indenyl,4-aryl-5-alkyl-1-indenyl, 2,6-dialkyl-4-aryl-1-indenyl,5,6-diaryl-1-indenyl, or 4,5,6-triaryl-1-indenyl.

The unsubstituted fluorenyl group may, for example, be a 9-fluorenylgroup, and the substituted fluorenyl group may, for example, be a7-methyl-9-fluorenyl group or a benz-9-fluorenyl group.

In the above formula (1), Y is carbon or silicon which has bonds to Aand B and which has substituents, and it is a methylene group or asilylene group having, as substituents, hydrogen or a C₁₋₁₅ hydrocarbongroup.

The substituents may be the same or different from each other. Further,Y may have a cyclic structure such as a cyclohexylidene group or acyclopentylidene group.

Preferably, Y is a substituted methylene group which has bonds to A andB and which is substituted by hydrogen or a C₁₋₁₅ hydrocarbon group. Thehydrocarbon group may, for example, be an alkyl group, an aryl group, acycloalkyl group or a cycloaryl group. The substituents may be the sameor different from each other.

Particularly preferably, Y is —CH₂—, —CMe₂—, —CEt₂—, —CPh₂—,cyclohexylidene or cyclopentylidene. Here, Me is a methyl group, Et isan ethyl group and Ph is a phenyl group.

X is hydrogen, a halogen atom, a C₁₋₁₅ alkyl group, a C₆₋₁₀ aryl group,a C₈₋₁₂ alkylaryl group, a silyl group having a C₁₋₄ hydrocarbonsubstituent, a C₁₋₁₀ alkoxy group, or a dialkylamide group having a C₁₋₆alkyl substituent. The halogen atom may, for example, be chlorine orbromine, the alkyl group may, for example, be a methyl group or an ethylgroup, and the aryl group may, for example, be a phenyl group. Thealkylaryl group may, for example, be a benzyl group, the silyl groupmay, for example, be trimethylsilyl, the alkoxy group may, for example,be a methoxy group, an ethoxy group or an isopropoxy group, and thedialkylamide group may, for example, be a dimethylamide group. X may bethe same or different from each other, or having a bond structurebetween X.

Especially when X is a dimethylamide group, the transition metalcatalyst component of the present invention can be produced by themethod disclosed in WO95/32979, whereby there is a merit that such acatalyst component can simply and inexpensively be produced. Namely, itcan be produced by a single step from a ligand compound and zirconiumtetrakisdimethylamide at a temperature of at least room temperature,where control is easy. Strictly, the transition metal catalyst componentproduced by this process is a racemic-form containing a substantialamount of meso-form as an impurity. However, inclusion of the meso-formin the catalyst gives no substantial influence in the present invention.

In the case of a transition metal complex wherein X is chlorine, ahighly costly process for reacting a dimethylamide type complex with adimethylamine hydrochloride at a low temperature, such as −78° C. isrequired, whereby the product will be expensive.

Further, when X is a dimethylamide, the speed for forming active speciesafter contacting with methylalumoxane as the cocatalyst, tends to beslightly slow as compared with a case where X is chlorine. This has animportant merit from the viewpoint of the production process in thatparticularly in a batch solution polymerization, in a polymerizationmethod of preliminarily dissolving a cocatalyst in the polymerizationsolution and introducing a transition metal compound to thepolymerization solution under prescribed condition to initiate thepolymerization, active species are gradually formed during thepolymerization, whereby abrupt generation of polymerization heatimmediately after the introduction of the catalyst can be reduced, andheat removal of the polymerization liquid can be facilitated.

M is zirconium, hafnium or titanium. Particularly preferred iszirconium.

The following compounds may be mentioned as specific examples of such atransition metal compound as catalyst component.

For example, dimethylmethylene bis(4,5-benz-1-indenyl)zirconiumdichloride (another name: dimethylmethylenebis(benz-e-indenyl)zirconiumdichloride), di-n-propylmethlenebis(4,5-benz-1-indenyl)zirconiumdichloride, di-i-propylmethylenebis(4,5-benz-1-indenyl)zirconiumdichloride, cyclohexylidenebis(4,5-benz-1-indenyl)zirconium dichloride,cyclopentylidenebis(4,5-benz-1-indenyl)zirconium dichloride,diphenylmethylenebis(4,5-benz-1-indenyl)zirconium dichloride,dimethylmethylene(cyclopentadienyl)(4,5-benz-1-indenyl)zirconiumdichloride, dimethylmethylene(1-indenyl)(4,5-benz-1-indenyl)zirconiumdichloride, dimethylmethylene(1-fluorenyl)(4,5-benz-1-indenyl)zirconiumdichloride, dimethylmethylene(4-phenyl-1-indenyl)(4,5-benz-1-indenyl)zirconium dichloride,dimethylmethylene(4-naphthyl-1-indenyl)(4,5-benz-1-indenyl)zirconiumdichloride, dimethylmethylenebis(5,6-benz-1-indenyl)zirconiumdichloride, dimethylmethylene(5,6-benz-1-indenyl)(1-indenyl)zirconiumdichloride, dimethylmethylenebis(4,7-benz-1-indenyl)zirconiumdichloride, dimethylmethylene(6,7-benz-1-indenyl)(1-indenyl)zirconiumdichloride, dimethylmethylenebis(4,5-naphtho-1-indenyl)zirconiumdichloride, dimethylmethylenebis(α-acetonaphtho-1-indenyl)zirconiumdichloride, dimethylmethylenebis(3-cyclopenta(c)phenanthryl)zirconiumdichloride,dimethylmethylene(3-cyclopenta(c)phenanthryl)(1-indenyl)zirconiumdichloride, dimethylmethylenebis(1-cyclopenta(1)phenanthryl)zirconiumdichloride, dimethylmethylene(1-cyclopenta(1)phenanthryl)(1-indenyl)zirconium dichloride,dimethylmethylenebis(4,5-benz-1-indenyl)zirconium bis(dimethylamide),and dimethylmethylene(1-indenyl)(4,5-benz-1-indenyl)zirconiumbis(dimethylamide), may be mentioned.

For example, dimethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconiumdichloride, di-n-propylmethylenebis(3-cyclopenta[c]phenanthryl)zirconiumdichloride, di-i-propylmethylenebis(3-cyclopenta[c]phenanthryl)zirconiumdichloride, cyclohexylidenebis(3-cyclopenta[c]phenanthryl)zirconiumdichloride, cyclopentylidenebis(3-cyclopenta[c]phenanthryl)zirconiumdichloride, diphenylinethylenebis(3-cylcopenta[c]phenanthryl) zirconiumdichloride, dimethylmethylene(4,5-benzo-1-indenyl)(3-cylcopenta[c]phenanthryl)zirconium dichloride,dimethylmethylene(5,6-benzo-1-indenyl)(3-cyclopenta[c]phenanthryl)zirconiumdichloride,dimethylmethylene(6,7-benzo-1-indenyl)(3-cyclopenta[c]phenanthryl)zirconiumdichloride,dimethylmethylene(cyclopentadienyl)(3-cyclopenta[c]phenanthryl)zirconiumdichloride, dimethylmethylene(1-fluorenyl)(3-cyclopenta[c]phenanthryl)zirconium dichloride,dimethylmethylene(4-phenyl-1-indenyl)(3-cyclopenta[c]phenanthryl)zirconiumdichloride,dimethylmethylene(4-naphthyl-1-indenyl)(3-cyclopenta[c]phenanthryl)zirconiumdichloride,dimethylmethylene(3-cyclopenta[c]phenanthryl)(4,5-naphto-1-indenyl)zirconiumdichloride, dimethylmethylene(3-cyclopenta[c]phenanthryl(α-acenaphto-1-indenyl)zirconium dichloride,dimethylmethylenebis(1-cyclopenta[1]phenanthryl)zirconium dichloride,di-n-propylmethylenebis (1-cyclopenta[1]phenanthryl)zirconiumdichloride, di-i-propylmethylenebis(1-cyclopenta[1]phenanthryl)zirconiumdichloride, cyclohexylidenebis(1-cyclopenta[1]phenanthryl)zirconiumdichloride, cyclopentylidenebis(1-cyclopenta[1]phenanthryl)zirconiumdichloride, diphenylmethylenebis(1-cyclopenta[1]phenanthryl)zirconiumdichloride, diphenylmethylene(4,5-benzo-1-indenyl)(1-cyclopenta[1]phenanthryl)zirconium dichloride,diphenylmethylene(5,6-benzo-1-indenyl)(1-cyclopenta[1]phenanthryl)zirconiumdichloride,diphenylmethylene(6,7-benzo-1-indenyl)(1-cyclopenta[1]phenanthryl)zirconiumdichloride,methylmethylene(cyclopentadienyl)(1-cyclopenta[1]iphenanthryl)zirconiumdichloride,dimethylmethylene(1-fluorenyl)(1-cyclopenta[1]phenanthryl)zirconiumdichloride,dimethylmethylene(4-phenyl-1-indenyl)(1-cyclopenta[1]phenanthryl)zirconiumdichloride,dimethylmethylene(4-naphthyl-1-indenyl)(1-cyclopenta[1]phenanthryl)zirconiumdichloride,dimethylmethylene(1-cyclopenta[1]phenanthryl)(4,5-naphtho-1-indenyl)zirconiumdichloride, dimethylmethylene(1-cyclopenta[1]phenanthryl)(α-acenaphtho-1-indenyl)zirconiumdichloride,dimethylmethylene(1-cyclopenta[1]phenanthryl)(3-cyclopenta[c]phenanthryl)zirconiumdichloride, and the like.

In the foregoing, zirconium complexes were exemplified, butcorresponding titanium complexes and hafnium complexes may also suitablybe used. Further, racemic-form or mixtures of racemic-form and meso-formmay also be employed. Preferably, racemic-form or pseudo racemic-formare employed. In such a case, D-isomers or L-isomers may be employed.

The following excellent characteristics are obtainable when an aromaticvinyl compound polymer or an aromatic vinyl compound-olefin copolymer isproduced by using the transition metal compound of the present inventionas a polymerization catalyst component.

The catalytic activities are high, and the polymer or the copolymer canbe obtained at a high productivity of a level of at least 1×10⁸(g/mol·transition metal catalyst) in the case where the aromatic vinylcompound content is less than 20 mol %, or at least 4.1×10⁷(g/mol·transition metal catalyst) when the aromatic vinyl compoundcontent is at least 20 mol % and less than 55 mol %.

Further, it is possible to produce a random copolymer having a higharomatic vinyl compound content, particularly an aromatic vinylcompound-ethylene random copolymer wherein the aromatic vinyl compoundcontent exceeds 55 mol %.

Especially when a polymerization catalyst comprising a transition metalcompound as catalyst component having a 3-cyclopenta(c)phenanthryl groupas ligand A or A and B, such asrac-dimethylmethylenebis(3-cyclopenta(c)phenanthryl)zirconiumdichloride, and a cocatalyst, is employed, it is possible to produce astyrene-olefin random copolymer, particularly a styrene-ethylene randomcopolymer, and an isotactic polystyrene, having a high molecular weight,under very high catalytic activities. In such a case, particularly withrespect to a copolymer wherein the aromatic vinyl compound content is atleast 50 mol %, it is possible to produce a copolymer having a weightaverage molecular weight of at least 100,000, preferably 200,000.Further, the styrene-ethylene random copolymer thereby obtained, has acharacteristic that it is a copolymer having a high random nature (lowalternating nature) as compared with a case with the same aromatic vinylcompound content under the same polymerization condition. Theisotacticity of the structure contained in the resulting polymer orcopolymer is very high.

Secondly, the present invention provides a transition metal compound ofthe following formula (2-1) or (2-2) as catalyst component for theproduction of an aromatic vinyl compound copolymer or an aromatic vinylcompound-olefin copolymer:

wherein A, B, Y, M and X are as defined with respect to the formula (1),wherein the angle (the bite angle) between metal M and the centroid ofeach cyclopentadienyl structure in A and B is at most 120°.

The bite angle can be obtained by X-ray diffraction of a single crystalof the transition metal catalyst component or by the followingcalculation method employing a computer.

SGI Origin Work Station was employed which has IRIX6.4 mounted as anoperation system and which has MIPS R10000 Processo Chip Revision 2.62×180 MHz IP27 processors as CPU.

The employed softwares were Molecular orbital method G94revision, E. 2,Gaussian 94 (manufactured by Gaussian Inc.) and Option (Geom, OPT, HF,DIRECT, STO-3G).

The results of the study carried out with respect todimethylmethylene(cyclopentadienyl)(fluorenyl)zirconium dichloride areshown below, which substantiate that the method of obtaining a biteangle by such a calculation, is proper.

Bite angle obtained by the above calculation method: 119° Bite angleobtained by single crystal X-ray diffraction method: 117.9°

Literature value: Macromol. Chem., Macromol. Symp., 48/49, 253 (1991).

The two values substantially agree, thus substantiating that thecalculation method is proper.

Calculation results Formulas Y Bite angle Formula (2-1)Dimethylmethylene 119′ group Dimethylsilylene 126′ group Formula (2-2)Dimethylmethylene 111′ group Dimethylsilylene 121′ group

By variously changing the structures of A and B, bite angles wereobtained by calculation, and such bite angles agreed to one anotherwithin a difference of 1°. Namely, the structures of A and B do notaffect the bite angle.

The present inventors have studied the content of an aromatic vinylcompound in the aromatic vinyl compound-olefin copolymer under the samecondition using various transition metal compound as catalystcomponents. As a result, it has been found that a very high aromaticvinyl compound content can be obtained when a transition metal catalystcomponent having a bite angle of at most 120° is employed.

Such a bite angle can be accomplished when in the above formula (2-1) or(2-2), Y is a methylene group having hydrogen or a C₁₋₁₅ hydrocarbongroup. In the case of the formula (2-2), two Y may be the same ordifferent.

Among a group of the above-mentioned transition metal catalystcomponents, the formula (2-1) represents a group of transition metalcatalyst components in which Y is a methylene group which has bonds to Aand B and which has, as substituents, hydrogen or a C₁₋₅ hydrocarbongroup.

In the case of the formula (2-2), the following compounds may bementioned as examples of such a transition metal catalyst component:

(1,2′-methylene)(2,1′-methylene)bis(4,5-benz-1-indenyl)zirconiumdichloride,(1,2′-isopropylidene)(2,1′-isopropylidene)bis(4,5-benz-1-indenyl)zirconium dichloride,(1,2-isopropylidene)(2,1′-methylene)bis(4,5-benz-1-indenyl)zirconiumdichloride,(1,2′-methylene)(2,1′-methylene)(1-indenyl)(4,5-benz-1-indenyl)zirconiumdichloride,(1,2′-isopropylidene)(2,1′-isopropylidene)(1-indenyl)(4,5-benz-1-indenyl)zirconiumdichloride,(1,2-isopropylidene)(2,1′-methylene)(1-indenyl)(4,5-benz-1-indenyl)zirconiumdichloride,(1,2′-methylene)(2,1′-methylene)(cyclopentadienyl)(4,5-benz-1-indenyl)zirconiumdichloride,(1,2′-isopropylidene)(2,1′-isopropylidene)(cyclopentadienyl)(4,5-benz-1-indenyl)zirconiumdichloride,(1,2′-isopropylidene)(2,1′-methylene)(cyclopentadienyl)(4,5-benz-1-indenyl)zirconiumdichloride,(1,2′-methylene)(2,1′-methylene)bis(3-cyclopenta(c)phenanthryl)zirconiumdichloride,(1,2′-isopropylidene)(2,1-isopropylidene)bis(3-cyclopenta(c)phenanthryl)zirconiumdichloride,(1,2′-isopropylidene)(2,1′-methylene)bis(3-cyclopenta(c)phenanthryl)zirconiumdichloride,(1,2′-methylene)(2,1′-methylene)bis(1-cyclopenta(1)phenanthryl)zirconiumdichloride,(1,2-isopropylidene)(1,2′-isopropylidene)bis(1-cyclopenta(1)phenanthryl)zirconiumdichloride, and(1,2′-isopropylidene)(2,1′-methylene)bis(1-cyclopenta(1)phenanthryl)zirconiumdichloride.

In the foregoing, zirconium complexes were exemplified, butcorresponding titanium complexes and hafnium complexes may also suitablybe used.

As such transition metal compound as catalyst components, racemic-formor pseudo racemic-form are preferably used. In such a case, D-isomers orL-isomers may be used. Further, a mixture of a racemic-form and ameso-form may also be used.

Thirdly, the present invention provides a polymerization catalyst forproducing an aromatic vinyl compound polymer or an aromatic vinylcompound-olefin copolymer, which comprises such a transition metalcompound and a cocatalyst and which provides a remarkably highproductivity, and an efficient method for producing an aromatic vinylcompound polymer and an aromatic vinyl compound-olefin copolymer,employing such a catalyst.

Particularly, it provides a polymerization catalyst for producing anaromatic vinyl compound polymer having isotactic stereoregularity in thepolymer structure or an aromatic vinyl compound-olefin copolymer havingan isotactic structure, and a method for producing an isotactic aromaticvinyl compound polymer and an aromatic vinyl compound-olefin copolymerhaving an isotactic structure, employing such a catalyst.

As the cocatalyst to be used in the present invention, a cocatalystwhich has been used in combination with a transition metal compound ascatalyst component, can be used. As such a cocatalyst, aluminoxane (oralumoxane), or a boron compound, is preferably employed.

Further, the present invention provides a method for producing anaromatic vinyl compound polymer or an aromatic vinyl compound-olefincopolymer wherein the cocatalyst to be used is an aluminoxane (oralumoxane) of the following formula (3) or (4):

wherein R is a C₁₋₅ alkyl group, a C₆₋₁₀ aryl group or hydrogen, m is aninteger of from 2 to 100, and the plurality of R may be the same ordifferent,

wherein R′ is a C₁₋₅ alkyl group, a C₆₋₁₀ aryl group or hydrogen, n isan integer of from 2 to 100, and the plurality of R′ may be the same ordifferent.

As the aluminoxane, methylalumoxane, ethylalumoxane ortriisobutylalumoxane, is preferably employed. Particularly preferred ismethylalumoxane. If necessary, a mixture of these different types ofalumoxanes, may be employed. Further, such an alumoxane may be used incombination with an alkylaluminum such as trimethylaluminum ,triethylaluminum or triisobutylaluminum, or with a halogen-containingalkylaluminum such as dimethylaluminum chloride.

Addition of an alkylaluminum to the catalyst is effective for removingsubstances which hinder polymerization, such as a polymerizationinhibitor in styrene, or moisture in the solvent, or for removingadverse effects against the polymerization reaction.

However, it is not necessarily required to add an alkylaluminum, if theamount of styrene, solvent, etc. is preliminarily reduced to a level notto influence the polymerization, by a known method such as distillation,bubbling with a dry inert gas or passing through a molecular sieve, orby increasing the amount of alumoxane to some extent or adding alumoxanein divided portions.

In the present invention, a boron compound may be used as a cocatalysttogether with the above transition metal compound as catalyst component.

The boron compound to be used as a cocatalyst may, for example, betriphenylcarbeniumtetrakis(pentafluorophenyl) borate{trityltetrakis(pentafluorophenyl)borate}, lithiumtetra(pentafluorophenyl)borate, tri(pentafluorophenyl)boran,trimethylammoniumtetraphenyl borate, triethylammoniumtetraphenyl borate,tripropylammoniumtetraphenyl borate, tri(n-butyl) ammoniumtetraphenylborate, tri (n-butyl)ammoniumtetra(p-tolyl)phenyl borate, tri(n-butyl)ammoniumtetra(p-ethylphenyl)borate,tri(n-butyl)ammoniumtetra(pentafluorophenyl)borate,trimethylammoniumtetra (p-tolyl) borate,trimethylammoniumtetrakis-3,5-tetramethylphenyl borate,triethylammoniumtetrakis-3,5-dimethylphenyl borate,tributylammoniumtetrakis-3,5-dimethylphenyl borate,tributylammoniumtetrakis-2,4-dimethylphenyl borate,aniliumtetrakispentafluorophenyl borate, N,N′-dimethylaniliuntetraphenylborate, N,N′-dimethylaniliumtetrakis(p-tolyl)borate,N,N′-dimethylaniliumtetrakis(m-tolyl)borate,N,N′-dimethylaniliumtetrakis(2,4-dimethylphenyl)borate,N,N′-dimethylaniliumtetrakis(3,5-dimethylphenyl)borate,N,N′-dimethylaniliumtetrakis(pentafluorophenyl)borate,N,N′-diethylaniliumtetrakis(pentafluorophenyl)borate,N,N′-2,4,5-pentamethylaniliumtetraphenyl borate,N,N′-2,4,5-pentaethylaniliumtetrraphenyl borate,di-(isopropyl)ammoniumtetrakispentafluorophenyl borate,di-cyclohexylammoniumtetraphenyl borate, triphenylphosphoniumtetraphenylborate, tri(methylphenyl)phosphoniurtetraphenyl borate,tri(dimethylphenyl)phosphoniumtetraphenyl borate,triphenylcarbeniumtetrakis (p-tolyl) borate,triphenylcarbeniumtetrakis(m-tolyl)borate,triphenylcarbeniumtetrakis(2,4-dimethylphenyl)borate,triphenylcarbeniumtetrakis(3,5-dimethylphenyl)borate,tropiliumtetrakispentafluorophenyl borate,tropiliumtetrakis(p-tolyl)borate, tropiliumtetrakis(m-tolyl)borate,tropiliumtetrakis(2,4-dimetyylphenyl)borate ortropiliuntetrakis(3,5-dimethylphenyl)borate.

Such a boron compound and the above-mentioned organoaluminum compoundmay be used at the same time.

Especially when a boron compound is used as a cocatalyst, addition of analkylaluminum compound such as triisobutylaluminum is effective for theremoval of impurities which adversely affect the polymerization, such aswater contained in the polymerization system.

Aromatic vinyl compounds to be used in the present invention may, forexample, be styrene and various substituted styrenes such asp-methylstyrene, m-methylstyrene, o-methylstyrene, o-t-butylstyrene,p-t-butylstyrene, p-chlorostyrene, o-chlorostyrene, and α-methylstyrene.Further, a compound having a plurality of vinyl groups in one molecule,such as divinylbenzene, may also be mentioned.

Industrially preferably, styrene, p-methylstyrene or p-chlorostyrene isused. Particularly preferably, styrene is used.

Further, as olefins to be used in the present invention, C₂₋₂₀α-olefinssuch as ethylene, propylene, 1-butene, 1-hexene, 1-methyl-1-pentene,1-octene and cyclic olefins such as cyclopentene, norbornene andnorbonadiene, may be mentioned. These olef ins may be used alone or incombination as a mixture of two or more of them. As such olefins,ethylene and propylene are preferred. In the following description,examples in which ethylene and propylene are used as olefins, will bereferred to.

For the production of a polymer or a copolymer of the present invention,the olefin, the above exemplified aromatic vinyl compound, thetransition metal compound as catalyst component as a metal complex andthe cocatalyst are contacted. As to the manner and order for contacting,an optional known method may be employed.

For the production of an aromatic vinyl compound polymer of the presentinvention, the above exemplified aromatic vinyl compound, the transitionmetal compound as catalyst component as a metal complex and thecocatalyst are contacted. As to the manner and order for contacting, anoptional known method may be employed.

As a method for the above polymerization or copolymerization, it ispossible to employ a method for carrying out the polymerization in aliquid monomer without using any solvent, or a method of using a singlesolvent or a mixed solvent selected from saturated aliphatic or aromatichydrocarbons or halogenated hydrocarbons, such as pentane, hexane,heptane, cyclohexane, benzene, toluene, ethylbenzene, xylene,chlorobenzene, chlorotoluene, methylene chloride or chloroform. Ifnecessary, batch polymerization, continuous polymerization, stepwisepolymerization, slurry polymerization, preliminary polymerization or gasphase polymerization may be employed.

Heretofore, when styrene is employed as a monomer component, it used tobe impossible to employ gas phase polymerization in view of its lowvapor pressure. However, when a catalyst of the present inventioncomprising a transition metal compound as catalyst component forpolymerization and a cocatalyst, is employed, the copolymerizationability of styrene will be remarkably high, whereby copolymerization ispossible even at a low styrene monomer concentration. Namely,copolymerization of an olefin with styrene is possible even under a lowstyrene partial pressure under a gas phase polymerization condition. Insuch a case, the transition metal catalyst component for polymerizationand the cocatalyst may be used as supported on a suitable known carrier.

The polymerization or copolymerization temperature is suitably from −78°C. to 200° C. A polymerization temperature lower than −78° C. isindustrially disadvantageous, and if the temperature exceeds 200° C.,decomposition of the metal complex is likely to take place, such beingundesirable. Industrially more preferably, the temperature is from −20to 160° C., particularly from 30 to 160° C.

The pressure for copolymerization is suitably from 0.1 to 200 atm,preferably from 1 to 50 atm, industrially particularly preferably, from1 to 30 atm.

When an organoaluminum compound is used as a cocatalyst, it ispreferably used in an aluminum atom/complex metal atom ratio of from 0.1to 100,000, preferably from 10 to 10,000, relative to the metal of thecomplex. If the ratio is smaller than 0.1, the metal complex can noteffectively be activated, and if it exceeds 100,000, such will beeconomically disadvantageous.

When a boron compound is used as a cocatalyst, it is used in an atomicratio of boron atom/complex metal atom of from 0.01 to 100, preferablyfrom 0.1 to 10, particularly preferably 1. If the atomic ratio is lessthan 0.01, the metal complex can not effectively be activated, and if itexceeds 100, such is economically disadvantageous.

The metal complex and the cocatalyst may be repared by mixing themoutside the polymerization tank, or they may be mixed in the tank duringpolymerization.

Fourthly, the present invention provides an aromatic vinylcompound-olefin copolymer obtained by using the transition metalcompound as catalyst component of the present invention or by the methodof the present invention.

Further, it provides an aromatic vinyl compound-ethylene randomcopolymer having a head-to-tail chain structure of at least two aromaticvinyl compound units, wherein the aromatic vinyl compound content isfrom 5 to 99.9 mol %. This copolymer is a novel copolymer and includesan aromatic vinyl compound-ethylene random copolymer obtained by usingthe transition metal compound as catalyst component of the presentinvention or by the method of the present invention. However, it is notparticularly limited by the transition metal catalyst component or themethod of the present invention.

In the following, reference is made to a styrene-ethylene randomcopolymer as an example of the aromatic vinyl compound-ethylene randomcopolymer of the present invention. However, the present invention is byno means restricted to such a styrene-ethylene copolymer.

The structure is determined by a nuclear magnetic resonance method(NMR).

The copolymer of the present invention has main peaks at the followingpositions in 13C-NMR using TMS as standard.

Namely, it shows peaks attributable to the main chain methylene and themain chain methine carbon in the vicinity of from 24 to 25 ppm, 27 ppm,30 ppm, from 34 to 37 ppm, from 40 to 41 ppm and from 42 to 46 ppm,peaks attributable to five atoms not bonded to the polymer chain amongphenyl groups in the vicinity of 126 ppm and 128 ppm, and a peakattributable to one carbon bonded to the polymer main chain among phenylgroups in the vicinity of 146 ppm.

The styrene-ethylene random copolymer of the present invention is astyrene-ethylene random copolymer having a styrene content of at least 5and less than 99.9%, more preferably at least 10 and less than 99.9%, bymolar traction, and the stereoregularity of phenyl groups in thealternating structure of styrene and ethylene of the following formula(5) contained in its structure is represented by an isotactic diad indexm of larger than 0.75, and the alternating structure index λ of thefollowing formula (i) is smaller than 70 and larger than 1, preferablysmaller than 70 and larger than 5:

λ=A3/A2×100  (i)

Here, A3 is the sum of areas of three peaks a, b and c attributable tothe carbons in styrene-ethylene alternating structure of the followingformula (5′). Further, A2 is the sum of areas of peaks attributable tothe main chain methylene and the main chain methine carbon, as observedwithin a range of from 0 to 50 ppm by 13C-NMR using TMS as standard:

wherein Ph is an aromatic group such as a phenyl group, and x is aninteger of at least 2, representing the number of repeating units,

wherein Ph is an aromatic group such as a phenyl group, and x is aninteger of at least 2, representing the number of repeating units.

In the styrene-ethylene random copolymer of the present invention, thestereoregularity of phenyl groups in the alternating copolymer structureof ethylene and styrene being an isotactic structure is meant for astructure wherein the isotactic diad index m (or a meso diad fraction)is more than 0.75, preferably more than 0.85, more preferably more than0.95.

The isotactic diad index m of the alternating copolymer structure ofethylene and styrene can be obtained by the following formula (ii) froman area Ar of the peak attributable to the r structure and an area Am ofthe peak attributable to the m structure appearing in the vicinity of 25ppm.

m=Am/(Ar+Am)  (ii)

The positions of the peaks may sometimes shift more or less dependingupon the measuring conditions or the solvent used.

For example, when chloroform-d is used as a solvent, and TMS is used asstandard, the peak attributable to the r structure appears in thevicinity of from 25.4 to 25.5 ppm, and the peak attributable to the mstructure appears in the vicinity of from 25.2 to 25.3 ppm.

Further, when 1,1,2,2-tetrachloroethane-d2 is used as a solvent, and thecenter peak (shift value of 73.89 ppm from TMS standard) of the tripletof the 1,1,2,2-tetrachloroethane-d2 is used as standard, the peakattributable to the r structure appears in the vicinity of from 25.3 to25.4 ppm, and the peak attributable to the m structure appears in thevicinity of from 25.1 to 25.2 ppm.

Here, the m structure represents a meso diad structure, and the rstructure represents a racemic diad structure.

In the styrene-ethylene random copolymer of the present invention, apeak attributable to the r structure of the alternating structure ofethylene and styrene is not substantially observed.

The chain structure of a head-to-tail bond of styrene units contained inthe styrene-ethylene random copolymer of the present invention is achain structure of at least two styrenes, preferably a chain structureof at least three styrenes, which can be represented by the followingstructure:

wherein n is an optional integer of at least 2, and Ph is aromatic groupsuch as phenyl group.

The chain structure wherein two styrene units are bonded head-to-tail,gives peaks in the vicinity of from 42.4 to 43.0 ppm and from 43.7 to44.5 ppm in the 13C-NMR measurement using TMS as standard and1,1,2,2-tetrachloroethane-d2 as a solvent.

The chain structure in which at least three styrene units are bondedhead-to-tail gives peaks also in the vicinity of from 40.7 to 41.0 ppmand front 43.0 to 43.6 ppm in a similar measurement. Accordingly, thechain structure in which at least two styrene units bonded head-to-tailgives a peak in the vicinity of from 40 to 45 ppm in a similarmeasurement.

On the other hand, in the conventional so-called pseudo randomcopolymer, no head-to-tail chain structure of styrene can be found evenin the vicinity of 50 mol % at which the styrene content is maximum.Further, even if homopolymerization of styrene is attempted by using acatalyst for the preparation of a pseudo random copolymer, no polymer isobtainable. Depending upon e.g. the polymerization condition, anextremely small amount of an atarctic styrene homopolymer may sometimesbe obtained. However, this is considered to have been formed by radicalpolymerization or cation polymerization by coexisting methylalumoxane oran alkylaluminum included therein.

Further, in the styrene-ethylene random copolymer of the presentinvention, the stereoregularity of phenyl groups in the head to tailchain structure of styrene units is isotactic.

The stereoregularity of phenyl groups in the head to tail chainstructure of styrene units being isotactic, is meant for a structurewherein the isotactic diad index 20 ms (or a mesa diad fraction) islarger than 0.5, preferably at least 0.7, more preferably at least 0.8.

The stereoregularity of the chain structure of styrene units isdetermined by the peak position of methylene carbon in the vicinity offrom 43 to 44 ppm as observed by 13C-NMR and by the peak position of themain chain proton as observed by 1H-HNR.

According to U.S. Pat. No. 5,502,133, methylene carbon of an isotacticpolystyrene chain structure appears in the vicinity of from 42.9 to 43.3ppm, but methylene carbon of a syndiotactic polystyrene chain structureappears in the vicinity of from 44.0 to 44.7 ppm. The positions of thesharp peak of methylene carbon of the syndiotactic polystyrene and thebroad peak at from 43 to 45 ppm of an atarctic polystyrene are close toor overlap the positions of peaks with relatively low intensity of othercarbon of the styrene-ethylene random copolymer of the presentinvention. However, in the present invention, a strong methylene carbonpeak is observed from 42.9 to 43.4 ppm, but no clear peak is observed inthe vicinity of from 44.0 to 44.7.

Further, according to U.S. Pat. No. 5,502,133 and the ComparativeExamples of the present invention, the peaks attributable to the mainchain methylene and methine proton in 1H-NMR, are observed at from 1.5to 1.6 ppm and from 2.2 to 2.3 ppm in the case of an isotacticpolystyrene and at from 1.3 to 1.4 ppm and from 1.8 to 1.9 ppm in thecase of a syndiotactic polystyrene.

With the copolymer of the present invention, peaks are observed at from1.5 to 1.6 ppm and at 2.2 ppm, and the result of this NMR analysisindicates that the styrene chain in the copolymer of the presentinvention has isotactic stereoregularity.

The isotactic diad index ms of the chain structure of styrene units canbe obtained by the following formula from the respective peaks ofmethylene carbon in the styrene chain structure by the 13C-NMRmeasurement or the main chain methylene and methine proton by the 1H-NMRmeasurement.

Namely, it can be obtained by the following formula (iii) from an areaAr′ of the peak attributable to the syndiotactic diad structure (rstructure) of each peak and an area Am′ of the peak attributable to theisotactic diad structure (m structure).

ms=Am′/(Ar′+Am′)  (iii)

The positions of the peaks may sometimes shift more or less dependingupon the measuring conditions or the solvent used.

The random copolymer in the present invention is a copolymer containinga chain structure wherein styrene units are bonded head-to-tail, a chainstructure wherein ethylene units are bonded to one another and astructure in which styrene units and ethylene units are bonded. Theproportions of these structures contained in the copolymer varydepending upon the content of styrene or polymerization conditions suchas the polymerization temperature.

As the styrene content decreases, the proportion of the chain structurein which styrene units are bonded head-to-tail, decreases. For example,in a case of a copolymer wherein the styrene content is not higher thanabout 20 mol %, it is difficult to directly observe a peak attributableto the chain structure wherein styrene units are bonded head-to-tail, bythe usual 13C-NMR measurement. However, it is evident that the chainstructure in which styrene units are bonded head-to-tail, is present inthe copolymer, although the amount may be small, even if the styrenecontent is not higher than 20 mol %, since it is possible to produce ahomopolymer having stereoregularity under high catalytic activity byhomopolymerization of styrene by using the transition metal catalystcomponent of the present invention or by the method of the presentinvention, i.e. it is essentially possible to form a chain structure inwhich styrene units are bonded head-to-tail, and since in the copolymer,the proportion of the chain structure in which styrene units are bondedhead-to-tail, continuously changes corresponding to the styrene contentof from 20 to 99 mol % at least by the 13C-NMR method. It is possible toobserve the chain structure wherein styrene units are bondedhead-to-tail, in the copolymer having a styrene content of not higherthan 20 mol %, by such a means as the 13C-NMR analysis using a styrenemonomer enriched with 13C.

The same applies to the chain structure of ethylene units.

It is known that peaks of methylene carbon of the structure derived frominversion of styrene in a conventional pseudo random copolymer having nostereoregularity, are present in two regions of from 34.0 to 34.5 ppmand from 34.5 to 35.2 ppm (for example, Polymer Preprints, Japan, 42,2292 (1993)).

With the styrene-ethylene random copolymer of the present invention, apeak attributable to methylene carbon of an inversion bond structurederived from styrene is observed in a region of from 34.5 to 35.2 ppm,but no substantial peak is observed at from 34.0 to 34.5 ppm.

This indicates one of the characteristics of the copolymer of thepresent invention and indicates that high stereoregularity of phenylgroups is maintained even with an inversion bond structure of thefollowing formula derived from styrene.

The weight average molecular weight of the styrene-ethylene randomcopolymer of the present invention is at least 60,000, preferably atleast 80,000, particularly preferably at least 180,000, when the styrenecontent is at least 5 mol % and less than 20 mol %, and at least 30,000,preferably at least 40,000, more preferably at least 100,000,particularly preferably at least 220,000, when the styrene content is atleast 20 mol % and less than 55 mol %, and at least 30,000, preferablyat least 40,000, when the styrene content is at least 55 mol % and atmost 99.9 mol %, thus being a practical high molecular weight. Themolecular weight distribution (Mw/Mn) is at most 6, preferably at most4, particularly preferably at most 3.

Here, the weight average molecular weight is a molecular weight ascalculated as polystyrene, obtained by GPC using standard polystyrene.The same applies in the following description.

The styrene-ethylene random copolymer of the present invention ischaracterized in that it has a highly stereoregular alternatingstructure of ethylene and styrene in combination with various structuressuch as ethylene chains having various lengths, inversion of styrene andhead to tail chains of styrene having various length. Further, with thestyrene-ethylene random copolymer of the present invention, theproportion of the alternating structure can be variously changed by thestyrene content in the copolymer within a range of λ of the aboveformula being more than 1 and less than 70. The stereoregularalternating structure is a crystallizable structure. Accordingly, thecopolymer of the present invention can be made to have variousproperties in the form of a polymer having a crystalline,non-crystalline, or partially or microcrystalline structure, bycontrolling the St content or the crystallinity by a suitable method.The value λ being less than 70 is important in order to impartsignificant toughness and transparency to a crystalline polymer, or toobtain a partially crystalline polymer, or to obtain a non-crystallinepolymer.

As compared with a conventional styrene-ethylene copolymer having nostereoregularity or no styrene chains, the copolymer of the presentinvention is improved in various properties such as the initial tensilemodulus, hardness, breaking strength and solvent resistance in variousSt content regions at various degrees of crystallinity and thus exhibitscharacteristic physical properties as a novel crystalline resin, athermoplastic elastomer or a transparent soft resin.

Further, by changing the styrene content, the glass transition point canbe changed within a wide range from −50° C. to 100° C.

Among copolymers of the present invention, a copolymer consisting mainlyof a chain structure of styrene units and an alternating structure ofstyrene units and ethylene units and having a styrene content of morethan 50 mol %, has high transparency and a high glass transitiontemperature and exhibits a high initial tensile modulus and excellentphysical properties as a plastic, since ethylene chains are little orvery little. Further, the alternating structure and a small amount ofethylene chains are relatively uniformly present in the chain structure,whereby the copolymer is excellent in impact resistance and showsexcellent toughness. Within a styrene content from 10 mol % to 75 mol %,preferably from 15 mol % to 60 mol %, the copolymer hascrystallizability due to the stereoregularity of the alternatingstructure and will be a copolymer having a partially or microcrystallinestructure, whereby it is capable of exhibiting physical properties as athermoplastic elastomer in the vicinity of the glass transitiontemperature or at a higher temperature.

Further, the styrene chain structure has an isotactic stereoregularity,whereby the copolymer is crystallizable, and can be crystallized by acommon crystallization treatment.

The styrene-ethylene random copolymer of the present invention can havea melting point of from about 50 to 130° C. (by DSC) within a range of astyrene content of from 10 to 75 mol %. Further, at a styrene content ofat least 90 mol %, it may have a melting point of from about 100 to 240°C. attributable to an isotactic polystyrene chain structure. The heat ofcrystal fusion is at a level of from 1 to 50 J/g in either case. Suchheat of crystal fusion and melting point by DSC can be changed to someextent by e.g. pretreatment conditions.

On the other hand, a conventional styrene-ethylene copolymer (a pseudorandom copolymer) having no stereoregularity or no styrene chain, has acrystal structure similar to polyethylene at a low styrene content, asshown in literature ANTEC, 1634 (1996), but with an increase of thestyrene content in the copolymer, the melting point and thecrystallinity will rapidly decrease, and at a styrene content of about15 mol %, the melting point becomes as low as about room temperature.Further, at a styrene content of from about 15 or 20 mol % to less than50 mol %, the copolymer will be amorphous having no melting point.

The styrene-ethylene random copolymer of the present invention whichcontains basically no dissolvable plasticizer or halogen, has a basiccharacteristic that it is highly safe.

Further, depending upon the polymerization conditions, etc., a smallamount of an atarctic homopolymer formed by polymerization of anaromatic vinyl compound by heat, radical or cation polymerization, maysometimes be contained, but such an amount should be less than 10 wt %of the total. Such a homopolymer can be removed by extraction with asolvent, but the copolymer may be used as it contains such ahomopolymer, provided that there will be no particular problem from theviewpoint of the physical properties.

The copolymer of the present invention has the following characteristicsat the respective styrene contents.

The copolymer with a styrene content of from 5 to 10 mol % has hightensile strength and transparency, is flexible and shows a nature as aplatomer or elastomer.

The copolymer with a styrene content of from 10 to 25 mol % has hightensile strength, elongation, transparency, flexibility and resiliencyand shows a nature as an elastomer.

The copolymers having the foregoing compositions are useful alone or inthe form of an alloy of the copolymers having different styrene contentsor in the form of an alloy with a polyolefin such as polypropylene, as astretch film for packaging.

The copolymer with a styrene content of from 50 to 99.9 mol % having amicrocrystalline structure or a low crystallinity, is a plastic havinghigh transparency and has a high shrinking property at a temperature ofat least the glass transition point and high dimensional stability at atemperature of not higher than the glass transition temperature, andthus it is useful as a shrinkable film for packaging.

Further, even if a fixed shape formed by once heating at a temperaturehigher than the melting point and then quenching to a temperature belowthe glass transition temperature, is deformed under a temperaturecondition of higher than the glass transition temperature and lower thanthe melting point and cooled to a temperature lower than the glasstransition temperature to fix the deformed shape, if it is heated againto a temperature higher than the glass transition temperature and lowerthan the melting point, it recovers the initial shape, Namely, thecopolymer has a shape memory property.

The copolymer with a styrene content of from 5 to 50 mol % is suitablyemployed for various applications as a substitute for soft polyvinylchloride, in the form of an alloy with a polyolefin such aspolypropylene or polyethylene, or with polystyrene or other resin, or inthe form of a partially crosslinked composition. Further, the copolymerwith this composition is useful as a compatibilizing agent for apolyolefin and a styrene resin, as an additive to a styrene resin or apolyolefin resin, as a modifier for rubber, as a component for anadhesive, or as bitumen (an additive to asphalt).

By changing the styrene content, the glass transition point of thecopolymer of the present invention can be optionally changed within arange of from −50 to 100° C., and the copolymer has a large tans peak inthe viscoelasticity spectrum and thus is useful as a vibrationpreventing material effective for a wide temperature range.

With the copolymer having a styrene content of about 50 mol %, it isrelatively easy to increase the crystallinity as compared withcopolymers with other ranges of the styrene content, and it exhibits ahigh initial elastic modulus although it is opaque, and thus is usefulas a novel partially crystalline plastic.

As a means for increasing the crystallinity, it is possible to adopt ameans such as annealing, addition of nucleating agent or alloying with apolymer having low Tg (such as wax).

In the foregoing, a styrene-ethylene random copolymer has been describedas a typical example of the aromatic vinyl compound-ethylene randomcopolymer of the present invention. However, the above description isgenerally applicable to the aromatic vinyl compound-ethylene randomcopolymer employing the above aromatic vinyl compound.

The present invention also provides an aromatic vinyl compound-propylenerandom copolymer wherein the aromatic vinyl compound content is from 5to 99.9 mol %, This copolymer is a novel copolymer and includes anaromatic vinyl compound-propylene random copolymer obtained by using thetransition metal compound as catalyst component of the presentinvention, or by the method of the present invention. However, such acopolymer is not restricted by the transition metal compound or themethod of the present invention.

Now, a styrene-propylene random copolymer will be described as anexample of the copolymer of the present invention.

The styrene-propylene random copolymer in the present invention is acopolymer having an aromatic vinyl compound content of from 5 to 99.9mol %.

Further, it is an aromatic vinyl compound-propylene random copolymercharacterized in that it has both chain structures of aromatic vinylcompound units and propylene units.

Further, it is an aromatic vinyl compound-propylene random copolymer,wherein the stereoregularity of the chain structures of the aromaticvinyl compound units and/or the propylene units, is isotactic.

The aromatic vinyl compound-olefin random copolymer of the presentinvention has a weight average molecular weight of at least 1,000,preferably at least 10,000, taking into consideration the physicalproperties as a copolymer (aromatic vinyl compound-ethylene randomcopolymer, is as described above). The molecular weight distribution(Mw/Mn) is at most 6, preferably at most 4, particularly preferably atmost 3.

The aromatic vinyl compound-olefin random copolymer of the presentinvention is not necessarily required to be a pure copolymer, and otherstructures may be contained, or any other monomer among theabove-mentioned α-olefins, aromatic vinyl compounds, and conjugateddienes such as butadiene, may be copolymerized, so long as the structureand the stereoregularity are within the above-mentioned ranges.

Further, depending upon the polymerization conditions, etc., a smallamount of an atarctic homopolymer formed by polymerization of anaromatic vinyl compound by heat, radical or cation polymerization, maysometimes be contained, but such an amount should be less than 10 wt %of the total. Such a homopolymer can be removed by extraction with asolvent, but the copolymer may be used as it contains such ahomopolymer, provided that there will be no particular problem from theviewpoint of the physical properties.

Further, for the purpose of improving the physical properties, it may beblended with other polymers. Further, copolymers of the presentinvention having different styrene contents may be blended.

Fifthly, the present invention provides a method for producing anaromatic vinyl compound polymer employing a transition metal compound ofthe above-mentioned formula (1) and cocatalyst.

The stereoregularity of the aromatic vinyl compound polymer obtained bythe method of the present invention is represented by an isotacticpentad index (mmmm) of at least 0.70, preferably at least 0.80, morepreferably at least 0.90. The isotactic diad index can be obtained froma peak attributable to carbon (PhCl) of a phenyl group bonded to themain chain of the polymer in the 13C-NMR measurement.

Namely, it is obtained from the proportion of the PhCl carbon peak areaattributable to the mmmm structure in the total of PhCl carbon peakareas. The PhCl carbon peak attributable to the mmmm structure appearsin the vicinity of 146.3 ppm when 1,1,2,2-tetrachloroethane-d2 is usedas a solvent, and the triplet center peak (73.89 ppm) of1,1,2,2-tetrachloroethane-d2 is used as standard.

The isotactic aromatic vinyl compound polymer obtained in the presentinvention has a weight average molecular weight of at least 1,000,preferably at least 10,000 taking into consideration the physicalproperties as a crystalline polymer. The molecular weight distribution(Mw/Mn) is at most 6, preferably at most 4, particularly preferably atmost 3.

By the method of the present invention, it is possible to obtain anisotactic aromatic vinyl compound polymer having a high stereoregularityunder high catalytic activities with little formation of atacticpolystyrene as a byproduct.

Sixthly, the present invention provides an aromatic vinylcompound-olefin alternating copolymer, preferably an aromatic vinylcompound-ethylene alternating copolymer, consisting mainly of analternating structure. This copolymer can be obtained by using thetransition metal compound as catalyst component of the presentinvention, or by the method of the present invention.

The aromatic vinyl compound-ethylene alternating copolymer obtainable bythe present invention, is an aromatic vinyl compound-ethylenealternating copolymer characterized in that the stereoregularity ofphenyl groups in the alternating structure of ethylene and an aromaticvinyl compound, is represented by an isotactic diad index m which is atleast 0.95, and the alternating structure index λ given by the aboveformula (i) is at least 70.

The isotactic diad (meso diad) index m of the alternating structure ofethylene and styrene in this copolymer, as an example of the aromaticvinyl compound-ethylene alternating copolymer of the present invention,can be obtained by the above-mentioned method employing the aboveformula (ii).

The weight average molecular weight obtained as calculated as standardpolystyrene, of the aromatic vinyl compound-ethylene alternatingcopolymer of the present invention, is preferably at least 10,000,taking into consideration the physical properties as a crystallineplastic. The molecular weight distribution (Mw/Mn) is at most 6,preferably at most 4, particularly preferably at most 3.

This copolymer has an aromatic vinyl compound content of from 46 to 54mol % and consists mainly of an alternating structure of ethylene andthe aromatic vinyl compound, which has high stereoregularity. It ischaracterized in that it further contains small amounts of variousstructures, such as ethylene chains of various lengths, heterogeneousbonds of the aromatic vinyl compound and chains of the aromatic vinylcompound, in a proportion not higher than a certain level.

The copolymer of the present invention has a high proportion of thealternating structure and high stereoregularity due to the alternatingstructure and accordingly has characteristics such as highcrystallinity, high melting point and a high crystallization speed.

The melting point of the copolymer obtainable by the DSC measurement isat least 130° C. and less than 210° C. preferably at least 150° C. andless than 210° C.

The copolymer of the present invention is capable of exhibiting highphysical properties as a crystalline or partially crystalline polymer.Therefore, it is expected to open up a novel application of acrystalline plastic as a substitute for polypropylene, a PET resin,nylon, etc.

For the production of the alternating copolymer of the presentinvention, the polymerization temperature is usually from −20 to +40° C.

Seventhly, the present invention provides an aromatic vinylcompound-ethylene copolymer having the following features:

(1) an aromatic vinyl compound content is from 1 mol % to 99 mol %.

(2) an aromatic vinyl compound unit-ethylene unit alternating structurehas a stereoregularity having an isotactic diad index of at least 0.75;and

(3) even after sufficiently subjecting to crystallization, acrystallinity derived from an aromatic vinyl compound-ethylenealternating structure is not observed.

The present invention further provides an aromatic vinylcompound-ethylene copolymer, characterized by having a head-to-tailchain structure of 2 or more aromatic vinyl compound units.

The present invention still further provides an aromatic vinylcompound-ethylene copolymer, wherein the aromatic vinyl compound contentis from 15 mol % to 85 mol %, more preferably from 40 mol % to 85 mol %,most preferably from 50 mol % to 85 mol %, and a melting point is notobserved between 70° C. to 200° C. by DSC measurement.

The present invention still further provides an aromatic vinylcompound-ethylene copolymer having an aromatic vinyl compound content offrom 15 mol % to 85 mol %, preferably from 40 mol % to 85 mol %, whereinan alternating structure index λ calculated by the following formula(i′) satisfies the following formula (ii′);

Formula (i):

λ=A3/A2×100

Formula (i^(Δ)):

in case of 15≦x<50 1≦λ<x−10

in case of 50≦x≦85 1≦λ<90−x

wherein x is an aromatic vinyl compound content (mol %), and in theformula (i), an A3 value is a total value of areas of three kinds ofpeaks a, b and c derived from an aromatic vinyl compound-ethylenealternating structure of the following formula (5′) in accordance with13C-NMR measurement, and an A2 value is a total value of peak areasderived from main chain methylene and main chain methine carbonsobserved in the range of from 0 to 50 ppm in accordance with 13C-NMRmeasurement based on TMS;

wherein Ph is an aromatic group, and x represents a number of repeatingunits and is an integer of at least 2.

The present invention still further provides an aromatic vinylcompound-ethylene copolymer, characterized by having peaks at 40-45 ppm,preferably at 40.4-41.0 ppm, 42.3-43.6 ppm, 43.0-43.6 ppm and 43.7-44.5ppm, more preferably at 42.3-43.6 ppm and 43.7-44.5 ppm, observed by13C-NMR measurement based on TMS.

The present invention still further provides an aromatic vinylcompound-ethylene copolymer, wherein the aroma tic vinyl compound unithaving a head-to-tail chain structure is at least 0.1%, preferably atleast 1.0% of the total amount of aromatic vinyl compound unitscontained in the copolymer and the aromatic vinyl compound content is atleast 1 mol % and less than 30 mol %.

The present invention still further provides an aromatic vinylcompound-ethylene copolymer, characterized by having a weight averagemolecular weight of at least 10,000, preferably at least 30,000, mostpreferably at least 80,000, in terms of molecular weight of standardpolystyrene calculation and a molecular weight distribution (Mw/Mn) ofat most 6. Also, in view of processibility of polymer, the weightaverage molecular weight is at most 1,000,000, preferably at most500,000.

The random copolymer of the present invention is a copolymer containingan aromatic vinyl compound unit chain structure having head-to-tailbonded, a chain structure having ethylene units bonded and a structurehaving an aromatic vinyl compound unit and an ethylene unit bonded.Depending on the styrene content or polymerization conditions such aspolymerization temperature, the ratio of these structures contained inthe copolymer varies. The ratio of these structures contained and thestructure distribution are not restricted by structure distributionaccording to specific statistical calculation.

Hereinafter, the aromatic vinyl compound-ethylene copolymer of thepresent invention is explained by taking a styrene-ethylene copolymer asan example for instance, but the present invention is not limitedthereto.

Its structure is determined in accordance with nuclear magneticresonance method (NMR method). The copolymer of the present inventionhas main peaks at the following positions determined in accordance with13C-NMR measurement based on TMS.

Peaks derived from main chain methylene and main chain methine carbonsare present in the vicinity of 24-25 ppm, in the vicinity of 27 ppm, inthe vicinity of 30 ppm, in the vicinity of 34-37 ppm, in the vicinity of40-41 ppm and in the vicinity of 42-46 ppm, and peaks derived from 5carbons not bonded to the polymer main chain among phenyl groups arepresent in the vicinity of 126 ppm and 128 ppm, and a peak derived fromone carbon bonded to the polymer main chain among phenyl groups ispresent in the vicinity of 146 ppm.

The aromatic vinyl compound content is determined in accordance with1H-NMR.

A head-to-tail bonded chain structure of styrene units contained in thestyrene-ethylene copolymer of the present invention is a chain structureof two or more styrenes expressed by the following structure.

wherein n is an integer of at least 2, and Ph is a phenyl group.

A chain structure having two styrene units bonded by head-to-tail, haspeaks in the vicinity of 42-43 ppm and 43-45 ppm, and preferably42.3-43.6 ppm and 43.7-44.5 ppm, in accordance with 13C-NMR measurementbased on TMS using tetrachloroethane-d as a solvent.

A chain structure having at least 3 styrene units bonded by head-to-tailhas peaks in the vicinity of 40-41 ppm and 43-44 ppm, and preferably40.4-41.0 ppm and 43.0-43.6 ppm, in accordance with the same measurementmethod.

Accordingly, a chain structure having at least 2 styrene units bonded byhead-to-tail, has peaks in the vicinity of 40-45 ppm, preferably40.4-41.0 ppm, 42.3-43.6 ppm, 43.0-43.6 ppm and 43.7-44.5 ppm.

On the other hand, a conventionally known pseudo random copolymer doesnot have a head-to-tail chain structure of styrene even when a styrenecontent reaches maximum and is in the vicinity of 50 mol %. Further,even when trying to homopolymerize styrene by using a catalyst forproducing a pseudo random copolymer, a polymer can not be obtained.There is a case wherein quite a small amount of atactic styrenehomopolymer can be obtained depending on polymerization conditions, butit should be understood that this is formed by radical polymerization orcation polymerization by methyl alumoxane or alkyl aluminum containedtherein.

Such an atactic styrene homopolymer can be easily separated by solventseparation.

In the styrene-ethylene copolymer of the present invention, an isotacticstructure having a stereoregularity of a phenyl group of ethylene andstyrene alternating copolymer structure is a structure having anisotactic diad index m (or mesodiad index) of higher than 0.75,preferably at least 0.85, more preferably at least 0.95.

The isotactic diad index M of the ethylene-styrene alternatingPolymerization structure c an be calculated from peak area Ar derivedfrom r structure and peak area m derived from m structure of methylenecarbon peak appearing in the vicinity of 25 ppm in accordance with thefollowing formula (ii).

m=Am/(Ar+Am)  (ii)

There is a case that peak positions are somewhat shifted depending onmeasurement conditions and a solvent used.

For example, in the case of using chloroform-d as a solvent and beingbased on TMS, the peak derived from r structure appears in the vicinityof 25.4-25.5 ppm and the peak derived from m structure appears in thevicinity of 25.2-25.3 ppm,

Also, in the case of using tetrachloroethane-d as a solvent and beingbased on the central peak (73.89 ppm) of triplet of tetrachloroethane-d,the peak derived from r structure appears in the vicinity of 25.3-25.4ppm and the peak derived from m structure appears in the vicinity of25.1-25.2 ppm.

The m structure means meso-diad structure, and the r structure meansracemi-diad structure.

In the styrene-ethylene copolymer of the present invention, peakattributable to the r structure is not substantially observed inethylene-styrene alternating structure.

The copolymer of the present invention does not have a crystal structurebased on ethylene-styrene alternating structure even after acceleratingcrystallization by a known method such as annealing, a nucleating agent,a crystallization assistant or the like. Particularly, a crystaldiffraction peak attributed to ethylene-styrene alternating structure isnot observed by X-ray diffraction method. The crystal diffraction peakbased on ethylene-styrene alternating structure means a diffraction peakobtained by using a Cu ray source, which has an intensity at least 3times higher than noise level in the range of from 15 to 40° of 2 θ, andis a diffraction peak having a peak area of at least 1% of halo peakarea or a peak having a half band width of at most 3° of 2 θ. The X-raydiffraction peak derived from ethylene-styrene alternating structure isdisclosed in JP-A-9-309925 and the literatures Macromol. Rapid Commun.,vol.19, 327 (1998) and Macromol. Rapid Commun., vol.17, 745 (1996). Thecopolymer of the present invention may contain a crystal structurederived from polyethylene in a low aromatic vinyl compound content zone(about at most 15 mol %), and may also contain a crystal structurederived from isotactic polystyrene in a high aromatic vinyl compoundcontent zone (about at least 90 mol %).

Further, the aromatic vinyl compound-ethylene copolymer of the presentinvention does not have a melting point between 70° C. and 200° C.according to DSC. measurement, and has an aromatic vinyl compoundcontent of preferably from 15 mol % to 85 mol %, more preferably from 40mol % to 85 mol %. The fact that a melting point is not observed between70° C. and 200° C. in accordance with DSC measurement, means that thereis no crystal structure (crystal structure derived from saidstyrene-ethylene alternating structure and crystal structure derivedfrom polyethylene chain structure and polystyrene chain structure)having a melting point in this temperature range.

The copolymer of the present invention has a low alternating propertyand a high random property since the alternating structure index λ valuesatisfies the formula (i^(Δ)) in various styrene contents and is lessthan 40 even at the styrene content of 50 mol %.

Therefore, in the copolymer of the present invention, a crystalstructure derived from isotactic styrene-ethylene alternating structureis not observed by X-ray diffraction method even after acceleratingcrystallization by a known method, Further, the copolymer of the presentinvention is characterized by having no melting point derived from anycrystal structure between 70° C. and 200° C. in accordance with DSCmeasurement.

Still further, the copolymer of the present invention is characterizedby having various structures therein, such as a chain structure ofethylene, a head-to-tail chain structure of styrene, a structure havinga styrene unit and an ethylene unit bonded and the like, in any styrenecontent ranges. Even when the styrene content in the copolymer is from50 mol % to 90 mol %, a chain structure of ethylene is observed inaccordance with usual 13C-NMR measurement. The copolymer of the presentinvention having a high styrene content and also having an ethylenechain at random and uniformly in the main chain of the copolymer, ischaracterized by having non-crystallinity, high impact strength and hightransparency.

When the styrene content in the copolymer is low and is from 1 mol % to50 mol %, two or more head-to-tail styrene chain structures are observedby usual 13C-NMR measurement, The copolymer of the present inventionhaving a head-to-tail styrene chain at random and uniformly in the mainchain of copolymer having such a low styrene content, is characterizedby destroying crystallinity of polyethylene chain and having highflexibility, high breaking strength and high transparency. In thepresent invention, an aromatic vinyl compound unit having a head-to-tailchain structure providing the above-mentioned peaks is at least 0.1%,preferably at least 1%, of the total amount of aromatic vinyl compoundunits contained in the copolymer when the aromatic vinyl compoundcontent is at least 1 mol % and less than 30 mol %.

The amount of the aromatic vinyl compound unit having a head-to-tailchain structure contained in the copolymer is expressed by a ratio x tothe total amount of aromatic vinyl compound units and is calculated bythe following formula.

x=xa/xb×100  (iv)

wherein xa is a total value of peak areas derived from the main chainmethine carbon of the head-to-tail chain structure of 2 or more aromaticvinyl compound units, for example, a total value of areas of peak (n)observed at 40.4-41.0 ppm and peak (j) observed at 42.3-43.6 ppm inaccordance with 13C-NMR measurement based on TMS, and xb is a totalvalue of peak areas derived from the main chain methine carbon of totalaromatic vinyl compound units contained in the copolymer.

Eighthly, the present invention provides a transition metal compound ofthe following formula (1′) as catalyst component:

wherein A′ is an unsubstituted or substituted cyclopentaphenanthrylgroup of the following formula K-2′ or K-3′:

wherein in the above formulas K-2′ and K-3′, each of R1 and R2 ishydrogen, a C₁₋₂₀ alkyl group, a C₆₋₁₀ aryl group, a C₇₋₂₀ alkylarylgroup, a halogen atom, OSiR₃, SiR₃ or PR₂ (wherein each R is a C₁₋₁₀hydrocarbon group), provided that a plurality of R1 and a plurality ofR2 may be the same or different, respectively, and each pair of adjacentR1 and adjacent R2 may together, with the atoms joining them, form a 5-to 8-member aromatic or aliphatic ring,

B′ is an unsubstituted or substituted cyclopentaphenanthryl group of thesame chemical formula as A′, an unsubstituted or substituted benzindenylgroup of the following formula K-4′, K-5′ or K-6′, or an unsubstitutedor substituted cyclopentadienyl group, an unsubstituted or substitutedindenyl group or an unsubstituted or substituted fluorenyl group, of thefollowing formula K-7′, K-8′ or K-9′:

wherein in the above formulas K-4′, K-5′ and K-6′ each of R3, R4 and R5is hydrogen, a C₁₋₂₀ alkyl group, a C₆₋₁₀ aryl group, a C₇₋₂₀ alkylarylgroup, a halogen atom, OSiR₃, SiR₃ or PR₂ (wherein each R is a C₁₋₁₀hydrocarbon group), provided that a plurality of R3, a plurality of R4and a plurality of R may be the same or different, respectively, andeach pair of adjacent R3, adjacent R4 and adjacent R5 may together, withthe atoms joining them, form a 5- to 8- member aromatic or aliphaticring, except for forming an unsubstituted cyclopentaphenanthryrenegroup,

wherein in the above formulas K-7′, K-8′ and K-9′ each of R6, R7 and R8is hydrogen, a C₁₋₂₀ alkyl group, a C₆₋₁₀ aryl group, a C₇₋₂₀ alkylarylgroup, a halogen atom, OSiR₃, SiR₃ or PR₂ (wherein each R is a C₁₋₁₀hydrocarbon group), provided that a plurality of R6, a plurality of R7and a plurality of R8 may be the same or different, respectively,

when both A′ and B′ are unsubstituted or substitutedcyclopentaphenanthryl groups, they may be the same or different,

Y′ is a methylene group or a boron residue, which has bonds to A′ and B′and which has, as substituents, hydrogen or a C₁₋₁₅ hydrocarbon group,wherein the substituents may be the same or different from each other,or Y′ may have, together with the substituents, a cyclic structureincluding a cyclohexylidene group or a cyclopentylidene group,

X is hydrogen, a halogen atom, a C₁-C₁₅ alkyl group, a C₆-C₁₀ arylgroup, a C₈-C₁₂ alkylaryl group, a silyl group having a C₁-C₄hydrocarbon substituent, C₁-C₁₀ alkoxy group or a dialkylamide grouphaving a C₁-C₆ alkyl substituent, and

M is zirconium, hafnium or titanium.

The polymerization catalyst comprising the transition metal component ofthe present invention and a cocatalyst can be suitably used forpreparing an aromatic vinyl compound-olefin copolymer, preferably anaromatic vinyl compound-ethylene copolymer, and further can be used forpolymerization or copolymerization of olefin. The term “olefin” usedherein means as mentioned above, Preferable examples of olefincopolymerization include copolymerization of ethylene-propylene,ethylene-butene, ethylene-1-hexene, ethylene-1-octene,ethylene-norbornene, propylene-butene, propylene-1-hexene, andpropylene-1-octene. The olefin copolymers thus obtained may further becopolymerized with dienes such as butadiene, isoprene,ethylene-ethylidenenorbornene and divinyl benzene. Examples of thesecopolymers include ethylene-propylene butadiene,ethylene-1-octene-butadiene, ethylene-propylene-ethylidene-norborneneand the like.

The polymerization catalyst comprising the transition metal catalystcomponent of the present invention and a cocatalyst achieves a very highcatalyst activity when used for polymerization and copolymerization ofolefin. That is, the catalyst produces at least 1,000 t of polymer permol of the complex for 1 hour, and this is the highest level amongconventionally known metallocene type catalysts. Further, thecarbon-crosslinking complex (isopropylidene-crosslinking complex) of thepresent invention achieves a high activity particularly to an olefinhaving a hindering substituent. The term “hindering substituent” means asubstituent having a carbon number of from 5 to 30. Examples of anolefin having such a hindering substituent include the above-mentionedstyrene monomer as well as norbornene, ethylidene-norbornene,vinylcyclohexene, vinylcyclohexane, vinylnaphthalene and the like,Further, the catalyst of the present invention can be suitably used forcopolymerization of these monomers with an olefin such as ethylene.

Also, when the polymerization catalyst comprising the transition metalcatalyst component of the present invention and a cocatalyst,particularly the polymerization catalyst comprising the transition metalcatalyst component in which B′ is an unsubstituted or substitutedcyclopentaphenanthryl group expressed by the same chemical formula asA′, and a cocatalyst, is used for copolymerization of aromatic vinylcompound-ethylene, there is produced the aromatic vinylcompound-ethylene copolymer introduced as the seventh invention, havingthe following features:

(1) an aromatic vinyl compound content is from 1 mol % to 99 mol %.

(2) an aromatic vinyl compound-ethylene alternating structure has astereoregularity having an isotactic diad index of at least 0.75; and

(3) even after sufficiently subjecting to crystallization, acrystallinity derived from an aromatic vinyl compound-ethylenealternating structure is not observed, and further there is produced thearomatic vinyl compound-ethylene copolymer, characterized by having ahead-to-tail chain structure of 2 or more aromatic vinyl compound units.

Now, the present invention will be described in further detail withreference to Examples. However, it should be understood that the presentinvention is by no means restricted to such specific Examples.

In the following description, Cp represents a cyclopentadienyl group,Ind a 1-indenyl group, BInd a 4,5-benz-1-indenyl group, Flu a9-fluorenyl group, Me a methyl group, Et an ethyl group, tBu a tertiarybutyl group, and Ph a phenyl group.

In the accompanying drawings:

FIG. 1 is a graph showing the productivity of the polymer per catalystin each Example or Comparative Example.

FIG. 2 is a GPC chart of the styrene-ethylene random copolymer obtainedin Example 2.

FIG. 3 is a DSC chart of the styrene-ethylene random copolymer obtainedin Example 2.

FIG. 4 is a 1H-NMR chart of the styrene-ethylene random copolymerobtained in Example 3.

FIG. 5 is a 1H-NMR chart of the styrene-ethylene random copolymerobtained in Example 4.

FIG. 6 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 3. Entire spectrum

FIG. 7 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 3. methine-methylene region

FIG. 8 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 4. Entire spectrum

FIG. 9 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 4. Methine-methylene region

FIG. 10 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 6. Entire spectrum

FIG. 11 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 6. Methine-methylene region

FIG. 12 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 9. Entire spectrum

FIG. 13 is a 13C-NMR chart of the styrene-thylene random copolymerobtained in Example 9. Methine-methylene region

FIG. 14 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 10. Entire spectrum

FIG. 15 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 10. Methine-methylene region

FIG. 16 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 12. Entire spectrum

FIG. 17 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 12. Methine-methylene region

FIG. 18 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 13. Entire spectrum

FIG. 19 is a 13C-NMR chart of the styrene-ethylene random copolymerobtained in Example 13. Methine-methylene region

FIG. 20 is a 13C-NMR chart of a styrene-ethylene pseudo random copolymerobtained in Comparative Example 1. Entire spectrum

FIG. 21 is a 13C-NMR chart of the styrene-ethylene pseudo randomcopolymer obtained in Comparative Example 1 Methine-methylene region

FIG. 22 is a 13C-NMR chart of a styrene-ethylene pseudo random copolymerobtained in Comparative Example 3. Entire spectrum

FIG. 23 is a 13C-NMR chart of the styrene-ethylene pseudo randomcopolymer obtained in Comparative Example 3. Methine-methylene region

FIG. 24 shows 13C-NMR charts in the vicinity of 45 ppm (methine carbonpeak).

FIG. 25 shows 13C-NMR charts in the vicinity of 25 ppm (alternatingstructure peak).

FIG. 26 shows X-ray diffraction patterns of the copolymers obtained inExamples 10 and 14.

FIG. 27 is a GPC chart of the styrene-propylene random copolymerobtained in Example 15.

FIG. 28 is a DSC chart of the styrene-propylene random copolymerobtained in Example 15.

FIG. 29 is a 13C-NMR chart of the styrene-propylene random copolymerobtained in Example 15. Methine-methylene-methyl region

FIG. 30 is a 13C-NMR chart of the styrene-propylene random copolymerobtained in Example 15, Phenyl C1 region

FIG. 31 is a 13C-NMR chart of the styrene-propylene random copolymerobtained in Example 17. Methine-methylene-methyl region

FIG. 32 is a 13C-NMR chart of the styrene-propylene random copolymerobtained in Example 17. Phenyl C1 region

FIG. 33 is a 13C-NMR chart of the styrene-propylene random copolymerobtained in Example 18. Methine-methylene-methyl region

FIG. 34 is a 13C-NMR chart of the styrene-propylene random copolymerobtained in Example 18. Phenyl C1 region

FIG. 35 is a 13C-NMR chart of the styrene polymer obtained in Example19.

FIG. 36 is a DSC chart of the styrene polymer obtained in Example 19.

FIG. 37 is an X-ray diffraction pattern of the styrene polymer obtainedin Example 19.

FIG. 38 is a 1H-NMR spectrum of the styrene-ethylene alternatingcopolymer obtained in Example 21.

FIG. 39 is a 13C-NMR spectrum of the styrene-ethylene alternatingcopolymer obtained in Example 21. Entire spectrum

FIG. 40 is a 13C-NMR spectrum of the styrene-ethylene alternatingcopolymer obtained in Example 21. Methine-methylene region

FIG. 41 is a GPC chart of the styrene-ethylene alternating copolymerobtained in Example 21.

FIG. 42 is a DSC chart of the styrene-ethylene alternating copolymerobtained in Example 22.

FIG. 43 is an X-ray diffraction pattern of the styrene-ethylenealternating copolymer obtained in Example 21.

FIG. 44 is a 13C-NMR spectrum of the styrene-ethylene random copolymerobtained in Example 23. Entire spectrum

FIG. 45 is a 13C-NMR spectrum of the styrene-ethylene random copolymerobtained in Example 23. Methine-methylene region

FIG. 46 is a 13C-NMR spectrum of the styrene-ethylene random copolymerobtained in Example 23. In the vicinity of 25 ppm.

FIG. 47 is a GPC chart of the copolymer obtained in Example 25.

FIG. 48 is a DSC chart of the copolymer obtained in Example 25.

FIG. 49 is an X-ray diffraction pattern of the copolymer obtained inExample 25.

FIG. 50 is an X-ray diffraction pattern of a copolymer having a crystalstructure derived from ethylene-styrene alternating structure.

FIG. 51 is 13C-NMR spectrum (methine-methylene zone) of the copolymerobtained in Example 26.

FIG. 52 is 13C-NMR spectrum (methine-methylene zone) of the copolymerobtained in Example 29.

The analyses of the copolymers obtained in the respective Examples andComparative Examples were carried out by the following methods.

The 13C-NMR spectrum was measured using TMS as standard, by using α-500manufactured by Nippon Denshi Kabushiki Kaisha and using a chloroform-dsolvent or a 1,1,2,2-tetrachloroethane-d2 solvent. Here, the measurementusing TMS as standard is the following measurement. Firstly, using TMSas standard, the shift value of the center peak of the triplet 13C-NMRpeak of 1,1,2,2-tetrachloroethane-d2 was determined. Then, the copolymerwas dissolved in the tetrachloroethane, and the 13C-NMR was measured,and each peak shift value was calculated using the triplet center peakof the tetrachloroethane as standard. The shift value of the tripletcenter peak of the tetrachloroethane was 73.89 ppm.

The 13C-NMR spectrum measurement for quantitative analysis of peakareas, was carried out by a proton gate decoupling method having NOEerased, by using pulses with a pulse width of 45° and a repeating timeof 5 seconds as standard.

When the measurement was carried out under the same conditions exceptthat the repeating time was changed to 1.5 seconds, the measured valuesof peak areas of the copolymer agreed to the values obtained in the casewhere the repeating time was 5 seconds, within a measurement errorrange.

The styrene content in the copolymer was determined by 1H-NMR. As theapparatus, α-500 manufactured by Nippon Denshi Kabushiki Kaisha andAC-250 manufactured by BRUKER Co. were used. The determination was madeby comparing the intensity of the peak (6.5 to 7.5 ppm) attributable tothe proton of a phenyl group and the proton peak (0.8 to 3 ppm)attributable to a methylene, methine and methyl group, measured by usingTMS as standard and chloroform-d or 1,1,2,2-tetrachloroethane-d2 as asolvent.

The molecular weights in Examples are obtained by CPC (gel permeationchromatography) as calculated as standard polystyrene.

A copolymer soluble in THF at room temperature, was measured by means ofHLC-8020, manufactured by TOSOH CORPORATION using THF as a solvents

A copolymer insoluble in THF at room temperature, was measured at 135°C. by means of 150CV apparatus manufactured by Waters Co. and using1,2,4-trichlorobenzene as a solvent, or measured at 145° C. by means ofHLC-8121 apparatus manufactured by TOSOR CORPORATION usingo-chlorobenzene as a solvent.

The DSC measurement was carried out by using DSC200, manufactured bySeiko Denshi K.K. in a nitrogen stream at a temperature raising rate of10° C./min.

The X-ray diffraction was measured by means of MXP-18 model high powerX-ray diffraction apparatus, source Cu rotating anode (wavelength:1.5405 Å), manufactured by Mac Science Company.

TEST EXAMPLES Preparation A of Transition Metal Compound

Rac-dimethylmethylenebis(4,5-benz-1-indenyl)zirconium dichloride(another name: rac-isopropylidenebis(4,5-benz-1-indenyl)zirconiumdichloride, hereinafter referred to as rac{BInd-C(Me)₂-Bind}ZrCl₂) ofthe following formula was prepared by the following method.

4,5-Benzindene was prepared in accordance with Organometallics, 13, 964(1994).

A-1 Preparation of 1,1-isopropylidene-4,5-benzindene

Preparation of 1,1-isopropylidene-4,5-benzindene was carried out withreference to the preparation of 6,6-diphenylfulvene disclosed in Can, J.Chem. 62, 1751 (1984), However, as starting materials, acetone was usedinstead of benzphenone, and 4,5-benzindene was used instead ofcyclopentadiene.

A-2 Preparation of isopropylidenebis 4,5-benz-1-indene

In an Ar atmosphere, 21 mol of 4,5-benzindene was dissolved in 70 ml ofTHF, and an equivalent amount of BuLi was added thereto at 0° C.,followed by stirring for 3 hours. THF having 21 mmol of1,1-isopropylidene-4,5-benzindene dissolved therein, was added thereto,followed by stirring at room temperature overnight. Then, 100 ml ofwater and 150 ml of diethyl ether were added thereto, followed byshaking, and the organic layer was separated and washed with a saturatedsodium chloride aqueous solution and then dried over sodium sulfate. Thesolvent was distilled off under reduced pressure. The obtained yellowsolid was washed with hexane and dried to obtain 3.6 g ofisopropylidenebis 4,5-benz-1-indene. The yield was 46%.

From the 1H-NMR spectrum measurement, it was found to have peaks at7.2-8.0 ppm (m,12H), 6.65 ppm (2H), 3.75 ppm (4H), and 1.84 ppm (6H).

The measurement was carried out using TMS as standard and CDCl₃ as asolvent.

A-3 Preparation of rac-dimethylmethylenebis(4,5-benz-1-indenyl)zirconiumdichloride

In an Ar atmosphere, 7.6 mmol of isopropylidenebis 4,5-benz-1-indene and7.2 mmol of zirconium tetrakisdimethylamide (Zr(NMe₂)₄) were chargedtogether with 50 ml of toluene, followed by stirring at 130° C. for 10hours. Toluene was distilled off under reduced pressure, and 100 ml ofmethylene chloride was added thereto, and the mixture was cooled to −78°C. Then, 14.4 mmol of dimethylamine hydrochloride was slowly addedthereto, and the temperature was slowly raised to room temperature,followed by stirring for 2 hours, After distilling off the solvent, theobtained solid was washed with pentane and then with a small amount ofTHF to obtain 0.84 g ofrac-dimethylmethylenebis(4,5-benz-1-indenyl)zirconium dichloride ofyellow orange color of the following formula. The yield was 21%.

From the 1H-NMR spectrum measurement, it was found to have peaks at 8.01ppm (m,2H), 7.75 ppm (m,2H) , 7.69 ppm (d,2H), 7.48-7.58 ppm (m,4H),7.38 ppm (d,2H), 7.19 ppm (d,2H), 6.26 ppm (d,2H) and 2.42 ppm (s,6H).

The measurement was carried out using TMS as standard and CDCl₃ as asolvent.

The elemental analysis was carried out by elemental analysis apparatus1108 model (manufactured by Fysons Co., Italy), whereby the resultsbeing C63.86% and H3.98% were obtained. The theoretical values wereC65.39% and H4.16%.

Preparation B of Transition Metal Compound as Catalyst Component

Rac-dimethylmethylene(1-indenyl)(4,5-benz-1-indenyl)zirconium dichloride(another name: rac-isopropylidene(1-indenyl)(4,5-benz-1-indenyl)zirconium dichloride, hereinafter referred to asrac{Ind-C(Me)₂-BInd}ZrCl₂) was prepared by the following method.

B-1 Preparation of isopropylidene(1-indene)(4,5-benz-1-indene)

In an Ar atmosphere, 14 mmol of indene was dissolved in 50 ml of THF,and an equivalent amount of BuLi was added at 0° C., followed bystirring for 10 hours. Then, 10 ml of THF having 13 mmol of1,1-isopropylidene-4,5-benzindene dissolved therein, was added thereto,followed by stirring at room temperature overnight. Then, 50 ml of waterand 100 ml of diethyl ether were added, followed by shaking, and theorganic layer was separated, washed with a saturated sodium chlorideaqueous solution and dried over sodium sulfate. Then, the solvent wasdistilled off under reduced pressure. The residue was further purifiedby column chromatography to obtain 2.5 g of isopropylidene(1-indene)(4,5-benz-1-indene). The yield was 59%.

B-2 Preparation ofrac-dimethylmethylene(1-indenyl)(4,5-benz-1-indenyl)zirconium dichloride

In an Ar atmosphere, 6.5 mmol of isopropylidene(1-indene)(4,5-benz-1-indene) and 6.5 mmol of zirconiumtetrakisdimethylamide {Zr(NMe₂)₄} were charged together with 40 ml oftoluene, followed by stirring at 130° C. for 10 hours. Then, toluene wasdistilled off under reduced pressure, and 100 ml of methylene chloridewas added thereto, and the mixture was cooled to −78° C. Then, 13 mmolof dimethylamine hydrochloride was slowly added thereto, and thetemperature was slowly raised to room temperature, followed by stirringfor 2 hours. Then, the solvent was distilled off, and the obtained solidwas washed with pentane and then with a small amount of methylenechloride to obtain 0.76 g ofrac-dimethylmethylene(1-indenyl)(4,5-benz-1-indenyl)zirconium dichlorideof orange color. The yield was 24%. From the 1H-NMR spectrummeasurement, it was found to have peaks at 7.05-8.04 ppm (m,10H)(provided a peak at 7.17 ppm is excluded), 7.17 ppm (d,H), 6.73 ppm(d,H), 6.25 ppm (d,H), 6.18 ppm (d,H), 2.41 ppm (m,3H), and 2.37 ppm(m,3H).

The measurement was carried out using TMS as standard and CDCl₃ as asolvent.

Preparation C of Transition Metal Compound as Catalyst Component

Rac-dimethylmethylenebis(4,5-benz-1-indenyl)zirconiumbisdimethylamide(another name:rac-isopropylidenebis(4,5-benz-1-indenyl)zirconiumbisdimethylamide,hereinafter referred to as rac{BInd-CMe₂-BInd}Zr(NMe₂)₂) of thefollowing formula andmeso-dimethylmethylenebis(4,5-benz-1-indenyl)zirconiumbisdimethylamide(another name:meso-isopropylidenebis(4,5-benz-1-indenyl)zirconiumbisdimethylamide,hereinafter referred to as meso{BInd-CMe₂-BInd}Zr(NMe₂)₂) were preparedas follows.

Into a 50 ml three-necked flask, a ligand (0.47 g, 1.25 mmol) wasintroduced and dissolved in 30 ml of toluene. Then, Zr(NMe₂)₄ (0.334 g,1.25 mmol) was added thereto, and the mixture was heated to 100° C. inan Ar stream and stirred for 3 days. The solvent was distilled off fromthe product, and the residue was washed with pentane to obtain a palebrown powder.

From the NMR measurement, it was found to be a mixture of a compositioncomprising 28% of a racemic-form, 13% of a meso-form and 59% of theligand.

rac-form: ¹H-NMR(C6D6, TMS) δ: 1.70(s,12H, NMe2), 1.77(s,6H, CMe2),5.91(d,2H,BIndC5), 6.73(d,2H,BIndC5), 6.8-7.7(m,12H,aromatic)

meso-form: ¹H-NMR(C6D6, TMS) δ: 0.75(s,6H,NMe2), 1.50(s,3H,CMe2),2.03(s,3H,CMe2), 2.71(s,6H,NMe2), 5.55(d,2H,BIndC5), 6.61(d,2H,BIndC5),6.8-7.7(m,12H,aromatic)

Preparation of Styrene-ethylene Random Copolymers Example 1

Into an autoclave having a capacity of 120 ml and equipped with amagnetic stirrer, which was evacuated and then filled with ethylene, 10ml of styrene and 8.4 μmol, based on Al atom, of methyl alumoxane(MMAO-3A, manufactured by TOSOH-AKZO K.K.) were charged.

While magnetically stirring at room temperature, 16 ml of a toluenesolution containing 8.4 νmol of the catalyst obtained in “Preparation Bof transition metal catalyst component”, rac{BInd-C(Me)₂-Ind}ZrCl₂, and0.84 mmol of triisobutylaluminum, was quickly charged by a syringe, andethylene was immediately introduced to raise the pressure to a totalpressure of 0.6 MPa (5 kg/cm²G). In 4 minutes after charging thecatalyst, the inner temperature rised to 46° C. by polymerization heat,but after 5 minutes, the temperature started to drop. While maintainingthe pressure at a level of 5 kg/cm²G, polymerization was carried out for1 hour. The polymerization solution was put into a large excess amountof dilute hydrochloric acid/methanol liquid to precipitate the polymer,which was dried under vacuum at 78° C. for 8 hours, to obtain 5 g of thepolymer.

Example 2

Polymerization was carried out by using an autoclave having a capacityof 10 lit. and equipped with a stirrer and a jacket for heating/cooling.800 ml of dry toluene and 4,000 ml of dry styrene were charged, and theinner temperature was raised to 50° C., followed by stirring. About 100l of nitrogen was used for bubbling to purge the interior of the system,and then 8.4 mmol of triisobutylaluminum and 84 mmol, based on Al, ofmethylalumoxane (MMAO-3A, manufactured by TOSOH-AKZO K.K.) were addedthereto. Ethylene was immediately introduced, and after the pressure wasstabilized at 0.2 MPa (1 kg/cm²G), about 50 ml of a toluene solutioncontaining 21 μmol of the catalyst obtained in “Preparation A oftransition metal catalyst component”,rac-dimethylmethylenebis(4,5-benz-1-indenyl)zirconium dichloride, and0.84 mmol of triisobutylaluminum, was added to the autoclave from acatalyst tank installed above the autoclave. While maintaining the innertemperature at 50° C. and the pressure at 0.2 MPa, polymerization wascarried out for 6 hours. After the polymerization, the obtained polymersolution was gradually put into vigorously stirred excess methanol toprecipitate the formed polymer, which was dried under reduced pressureat 60° C. until no weight change was observed any longer, to obtain1,000 g of the polymer.

Examples 3 to 9

Polymerization and post treatment were carried out in the same manner asin Example 2 under the conditions shown in Table 1 by using, as acatalyst, the catalyst obtained in “Preparation A of transition metalcompound as catalyst component”,rac-dimethylmethylenebis(4,5-benz-1-indenyl)zirconium dichloride.

However, in Example 7, methylalumoxane (PMAO, manufactured by TOSOH-AKZOK.K.) was used as a cocatalyst.

Further, in Examples 4 and 5, ethylene was diluted with nitrogen gas tolower the ethylene partial pressure, whereby polymerization was carriedout.

Examples 10 and 11

Polymerization and post treatment were carried out in the same manner asin example 2 under the conditions shown in Table 1 by using, as acatalyst, the catalyst obtained in “Preparation B of transition metalcatalyst component”,rac-dimethylmethylene(1-indenyl)(4,5-benz-1-indenyl)zirconiumdichloride.

Example 12

Polymerization and post treatment were carried out in the same manner asin Example 2 under the conditions shown in Table 1, except that thecatalyst was changed to the complex mixture of rac-form and meso-form,obtained in “Preparation C of transition metal compound as catalystcomponent”, which was weighed so that it contained 8.4 μmol ofrac-dimethylmethylenebis(4,5-benz-1-indenyl)zirconiumbisdimethylamide,and used for polymerization.

Example 13

8.4 μmol of rac{BInd-C(Me)₂-Ind}ZrCl₂ obtained in “Preparation B oftransition metal compound as catalyst component” was dissolved in 20 mlof a toluene solution containing 1 mmol of triisobutylaluminum. Then, 20ml of a toluene solution having 8.4 μmol of Ph₃CB(C₆F₅)₄ dissolvedtherein, was added thereto to obtain a catalyst solution. Into anautoclave having a capacity of 1 lit. and equipped with a stirrer, 400ml of toluene and 80 ml of styrene were charged, and the catalystsolution was introduced under an ethylene pressure of 10 kg/cm²G) at aninner temperature of 17° C. Polymerization started immediately, and theinner temperature rised to the maximum of 74° C. by heat generation.Polymerization was carried out for one hour while maintaining thepressure at a level of 1.1 MPa (10 kg/cm²G) during the polymerization.Post treatment was carried out in the same manner as in Example 2, toobtain 53 g of a polymer.

Example 14

Polymerization was carried out by using a polymerization reactor havinga capacity of 150 lit. and equipped with a stirrer and a jacket forheating/cooling.

60 lit. of dry cyclohexane and 12 lit. of dry styrene were charged, andthe inner temperature was raised to 33° C. with stirring. Then, 84 mmolof triisobutylaluminum and 840 mmol, based on Al, of methylalumoxane(MMAO-3A, manufactured by TOSOH-AKZO K.K.) were added thereto. Ethylenewas immediately introduced, and after the pressure was stabilized at 1.0MPa (9 kg/cm²G), about 100 ml of a toluene solution containing 78 μmolof the catalyst obtained in “Preparation A of transition metal compoundas catalyst component”,rac-dimethylmethylenebis(4,5-benz-1-indenyl)zirconium dichloride, and 2mmol of triisobutylaluminum, was added to the polymerization reactorfrom a catalyst tank installed above the polymerization tank. As heatgeneration started immediately, cooling water was introduced to thejacket. The inner temperature rose to the maximum of 80° C., butthereafter was maintained at about 70° C., and polymerization wascarried out for 2.5 hours while maintaining the pressure at 1.0 MPa.

After completion of the polymerization, the obtained polymerizationsolution was deaerated and then treated by a crumb forming method asfollows to recover the polymer.

The polymerization solution was put into 300 lit. of vigorously stirredwater heated to 85° C. containing a dispersant (Pluronic, tradename)over one hour. Then, it was stirred at 97° C. for one hour, and then thehot water containing the crumb was put into cool water to recover thecrumb. The crumb was dried in air at 50° C. and then deaerated undervacuum at 60° C. to obtain 12.8 kg of a polymer having a good crumbshape and having a size of about a few mm.

Comparative Example 1

With reference to J. Am. Chem. Soc., 110, 6255 (1988) and J. Organomet.Chem, 459, 117 (1993), EWEN type Zr complex, diphenylmethylene(fluorenyl)(cyclopentadienyl)zirconium dichloride of the followingformula, another name: {Flu-CPh₂-Cp}ZrCl₂, was prepared.

Into an autoclave having a capacity of 120 ml and equipped with astirrer, which was substituted by nitrogen and then by ethylene, 20 mlof styrene and 4.6 mmol of methylalumoxane (MMAO-3A, manufactured byTOSOH-AKZO K.K.) were charged and heated to 40° C. While maintaining theethylene pressure at atmospheric pressure, 46 μmol of the above{Flu-CPh₂-Cp}ZrCl₂ dissolved in 20 ml of toluene, was added, andpolymerization was carried out for one hour. During the polymerization,the temperature was maintained to be 40° C., and the presser wasmaintained to be atmospheric pressure (0 kg/cm²G). Post treatment afterthe polymerization was carried out in the same manner as in Example 1,to obtain 2.2 g of a white polymer.

Comparative Example 2

Polymerization and post treatment were carried out in the same manner asin Example 2 under the conditions shown in Table 1 by using the abovediphenylmethylene (fluorenyl) (cyclopentadienyl)zirconium dichloride.From the amount of consumption of ethylene monitored, polymerization wasfound to be substantially completed in 4 hours.

Comparative Example 3

With reference to JP-A-7-053618, CGCT (constrained geometricalstructure) type Ti complex, (tertiarybutylamide)dimethyl(tetramethyl-η5-cyclopentadienyl)silanetitaniumdichloride, another name; {CpMe₄-SiMe-NtBu}TiCl₂, was prepared.

Polymerization and post treatment were carried out in the same manner asin Example 2 under the conditions shown in Table 1 by using, as acomplex, the CGCT (constrained geometrical structure) type Ti complex,(tertiarybutylamide)dimethyl(tetramethyl-η5-cyclopentadienyl)silanetitaniumdichloride. From the amount of consumption of ethylene monitored,polymerization was found to be substantially completed in 3 hours.

Comparative Examples 4 and 5

Polymerization and post treatment were carried out in the same manner asin Example 2 under the conditions shown in Table 1 by using, as acomplex, the CGCT (constrained geometrical structure) type Ti complex,(tertiary butylamide) dimethyl (tetramethyl-η5-cyclopentadienyl)silanetitanium dichloride. From the amount of consumption of ethylenemonitored, in both Comparative Examples 4 and 5, polymerization wasfound to be substantially completed in 2.5 hours.

Comparative Example 6

With reference to Organometallics, 13, 964 (1994),rac-dimethylsilylenebis(2-methyl-4,5-benzindenyl)zirconium dichloride,another name ras{2-Me-BInd-SiMe₂-2-Me-BInd}ZrCl₂, was prepared.

Polymerization and post treatment were carried out in the same manner asin Example 2 under the conditions shown in Table 1 by using, as acomplex, dimethylsilylenebis(2-methyl-4,5-benzindenyl)zirconiumdichloride. From the amount of consumption of ethylene monitored, thepolymerization was found to be substantially completed in 2 hours.

Comparative Example 7

With reference to Angew. Chem. Int. Ed. Engl. 24, 507 (1985),rac-ethylenebis(1-indenyl)zirconium dichloride, another name:rac{Ind-Et-Ind}ZrCl₂, was prepared.

Polymerization and post treatment were carried out in the same manner asin Example 2 under the conditions shown in Table 1 by using, as acomplex, rac-ethylenebis(1-indenyl)zirconium dichloride. From the amountof consumption of ethylene monitored, polymerization was found to besubstantially completed in 6 hours.

Table 1 shows the copolymerization results.

FIG. 1 shows the productivity of a polymer per catalyst in each Exampleor Comparative Example wherein polymerization was carried out by using a10 lit. autoclave. It is evident that the catalysts in Examples exhibitremarkably high productivity as compared with the catalysts ofComparative Examples.

TABLE 1 Cocata- Amount Amount of lyst Amount of of Ethylene ProductivitySt content Cata- catalyst (μmol) solvent styrene pressure PTE PTI Yield(g/mol-cata- (mol %) Examples lyst (μmol) MAO (ml) (ml) MPa (° C.) (hr)(g) lyst)/10^(b) (%) Ex. 1 B 8.4 8.4 T 26 10 0.6 15-46 1 5 0.49 41.0 Ex.2 A 21 84 T 800 4000 0.2 50 6 1000 47.6 53.8 Ex. 3 A 21 84 T 800 40000.15 50 8 1013 48.2 55.5 Ex. 4 A 84 84 T 800 4000 0.02 50 5 150 1.8 72.9Ex. 5 A 84 84 T 800 4000 0.005 50 8 98 1.2 92.0 Ex. 6 A 2.1 84 T 4000800 1.1 50 4 874 416 15.5 Ex. 7 A 0.84 8.4 T 4000 800 1.1 50 5 464 55011.5 Ex. 8 A 2.1 8.4 T 4400 400 1.1 50 4 970 462 7.0 Ex. 9 A 8.4 84 T2400 2400 1.1 50 5 1320 157 37.1 Ex. 10 B 21 84 T 800 4000 0.2 50 6 70033.3 47.1 Ex. 11 D 8.4 84 T 2400 2400 1.1 50 5 870 104 31.8 Ex. 12 C 8.484 T 2400 2400 1.1 50 2.5 1280 152 33.9 Ex. 13 B 8.4 0.0084* T 400 801.1 17-74 1 53 6.3 25.8 Ex. 14 A 78 840 C 60L 12L 1.0 33-81 2.5 12.8 kg164 27.9 Comp. D 46 4.6 T 20 20 0.1 40 1 2.2 0.05 43.0 Ex. 1 D Comp. D164 164 T 800 4000 0.4 50 4 286 1.7 21.1 Ex. 2 Comp. E 84 84 T 800 40000.2 50 3 570 6.8 49.8 Ex. 3 Comp. E 21 84 T 3300 1500 1.1 50 2.5 55026.2 13.0 Ex. 4 Comp. E 2.1 84 T 3500 1300 1.1 50 2.5 60 28.8 9.0 Ex. 5Comp. F 8.4 84 T 4000 800 1.1 50 2 44 5.2 <2 Ex. 6 Comp. C 84 84 T 8004000 0.2 50 6 385 4.6 9.5 Ex. 7 T: Toluene  C: Cyclohexane Transitionmetal compounds used as catalysts A: rac-dimethylmethylenebis(4,5-benz-1-indenyl) zirconium dichloride B:rac-dimethylmethylene(1-indenyl) (4,5-benz-1-indenyl) zirconiumdichloride C: rac-dimethylmethylenebis (4,5-benz-1-indenyl) zirconiumbis (dimethylamide) D: Diphenylmethylene(cyclopentadienyl) (fluorenyl)zirconium dichloride E: Tertiary butylamide dimethyl(tetramethyl-η5-cyclopentadienyl)silanetitanium dichloride F:rac-dimethylsilylenebis (2-methyl-4,5-benz-1-indenyl)zirconiumdichloride G: rac-ethylenebis(1-indenyl)zirconium dichloride *:Ph3CB(C6F5)4 was used instead of MAO. PTE: Polymerization temperaturePTI: Polymerization time

Table 2 shows the styrene content, the molecular weight obtained by GPC,and the glass transition point and the melting point obtained by DSC, ofthe obtained polymer.

TABLE 2 Glass transi- St tion Melting content Mw Mn temp. point Examples(mol %) /10⁴ /10⁴ Mw/Mn (° C.) (° C.) Ex. 1 41.0 22.1 13.2 1.7 —79,130 6.8 1.5 4.5 Ex. 2 53.8 24.6 12.6 2.0 25 102 Ex. 3 55.5 16.9 9.01.9 34 110 Ex. 4 72.9 5.2 2.7 1.9 59 72 Ex. 5 92.0 4.8 2.8 1.7 70 * Ex.6 15.5 12.0 8.0 1.5 −24 83, 60 Ex. 7 11.5 18.5 8.6 2.2 −2 5 75 Ex. 8 7.011.8 6.0 2.0 −35 90 Ex. 9 87.1 38.0 14.6 2.3 −1 103 Ex. 10 47.1 25.014.4 1.7 17 113 Ex. 11 31.8 30.0 16.7 1.8 −6 83 Ex. 12 33.9 30.8 15.52.3 7 95 Ex. 13 25.8 19.4 8.3 2.3 −24 98 Ex. 14 27.9 15.8 6.3 2.5 −11 71Comp. 43.0 14.6 8.4 1.7 0 * Ex. 1 Comp. 21.1 50.2 18.6 2.7 −21 25 Ex. 2Comp. 49.8 35.3 17.0 2.1 31 * Ex. 3 Comp. 13.0 18.7 12.1 1.5 −22 63 Ex.4 Comp. 9.0 1.5 0.9 1.7 −27 95 Ex. 5 Comp. <2 — — — — 126 Ex. 6 Comp.9.5 5.0 2.4 2.0 −27 112 Ex. 7 *: No melting point was observed. : Thepeak was a two head peak, and peak separation was carried out fordetermination.

FIGS. 2 and 3 show a GPC chart and a DSC chart of the copolymer obtainedin Example 2 as a typical example of the styrene-ethylene copolymer ofthe present invention.

In the GPC measurements of polymers obtained in various Examples exceptfor Example 1 wherein the polymerization scale was very small, the GPCcurves obtained by different detectors (RI and UV) agreed within anexperimental error range, as shown in FIG. 2. This indicates that eachcopolymer has an extremely uniform compositional distribution.

Further, the glass transition point obtained by DSC in Table 2, was one.This also indicates a uniform composition of the copolymer.

1H-NMR spectra of the polymers obtained in Examples 3 and 4 are shown inFIGS. 4 and 5.

The styrene-ethylene random copolymer of the present invention isspecifically a copolymer containing a typical structure represented bythe following formula in an optional proportion.

In the methine and methylene carbon regions in the 13C-NMR spectra,peaks attributable to the following, are shown. Symbols a to o aresymbols representing carbon atoms shown in the chemical structures ofthe formulas (2) and K-32 to K-40.

Peaks attributable to the following, are shown using the center peak(73.89 ppm) of the triplet of 1,1,2,2-tetrachloroethane-d2 as standard.

(1) Alternating structure of styrene and ethylene

wherein Ph is a phenyl group, and x is an integer of at least 2,representing the number of repeating units.

Namely, it represents a structure of the following formula whichcomprises methine carbon atoms bonded to the Ph groups and three methinecarbon atoms sandwiched therebetween.

For simplicity, hydrogen atoms are omitted.

(2) Chain structure of ethylene

(3) Structure comprising an ethylene chain and one unit of styrene

(4) Structure comprising inversion (tail-to-tail structure) of styreneunits

(5) Structure comprising ethylene units or an ethylene chain, and ahead-to-tail chain of two styrene units

Or, a structure wherein styrene units and styrene-ethylene alternatingstructural units are randomly bonded.

Styrene unit:

Alternating structural unit;

6) Structure comprising a head-to-tail chain of at least three styreneunits

25.1-25.2 ppm (c)

36.4-36.5 ppm (b)

44.8-45.4 ppm (a)

29.4-29.9 ppm (g)

36.5-36.8 ppm (e)

27.2-27.6 ppm (f)

45.4-46.1 ppm (d,h)

34.5-34.9 ppm (I)

42.4-43.0 ppm (j)

43.7-44.5 ppm (k)

35.6-36.1 ppm (l)

24.0-24.9 ppm (m)

40.7-41.0 ppm (n)

43.0-43.6 ppm (o)

The above peaks may have some shifts, micro structures of peaks or peakshoulders, due to an influence of the measuring conditions, the solventused, etc. or due to a distanced effect from the adjacent structure.

Attribution of these peaks was made by literatures such asMacromolecules, 13, 849 (1980), Stuf. Surf. Sci.

Catal., 517, 1990, J. Appln. Polymer Sci., 53, 1453 (1994), J. PolymerPhys. Ed., 13, 901 (1975), Macromolecules, 10, 773 (1977), PolymerPreprints, Japan, 42, 292 (1993), EP-416815 and JP-A-4-130114, and bythe peak shift prediction by the 13C-NMR Inadequate method, the DEPTmethod, and the 13C-NMR data base STN (Specinfo).

As typical examples, the 13C-NMR charts of Examples 3, 4, 6, 9, 10, 12and 13 and Comparative Examples 1 and 3, are shown in FIGS. 6 to 23. The13C-NMR peak positions of copolymers obtained by typical Examples adComparative Examples, are shown in Table 3.

The enlarged 13C-NMR spectra of Examples and Comparative Examples areshown in FIGS. 24 and 25. However, only in the spectrum of ComparativeExample 1, CDCl₃ is used as the solvent, and for the purpose ofcomparing with other spectra (1,1,2,2-tetrachloroethane-d2), the peakpositions are shown as corrected.

TABLE 3 Main peak shift values (ppm) by 13C-NMR, obtained by using1,1,2,2-tetrachloroethane-d2 as a solvent Attribu- tion Example 1Example 3 Example 4 Example 6 Example 9 Example 10 Example 12 Example 13c m 25.11 25.11 25.10 25.12 25.12 25.11 25.11 25.12 ˜25.22 ˜25.15 ˜25.16r — — — — — — — — a mm 45.25 45.26 45.20 45.37 45.27 45.26 45.16 45.27mr — — — — — — — — rr — — — — — — — — b m (m) 36.46 36.45 36.45 36.4836.46 36.45 36.43 36.46 m (r) — — — Over- — — Over- Over- r (m) — — —lapped — — lapped lapped r (r) — — — with — — with with block blockblock peaks peaks peaks g 29.3-29.7 29.4-29.7 — 28.4-29.6 29.3-29.729.3-28.7 29.4-29.8 29.3-29.5 n a) 40.8 40.9 40.7 — — — — — b) — — — — —— — — o a) 43.1 43.3 42.8 — — — — — 43.2 43.5 43.5 — — — b) — — — — — —— — j 42.9 42.7 42.4 — 42.9 42.9 42.7 42.9 42.9 42.8 k 43.9 43.9 43.6 —44.0 43.9 43.9 44.0 44.0 Attribu- Comp. Comp. Comp. tion Ex. 1 Ex. 1 c)Ex. 3 c m 25.16 25.30 25.11 r 25.30 25.17 25.30 a mm 45.25 45.45 45.20mr 45.32 45.56 45.29 rr 45.41 45.70 45.41 b m (m) Many Many 36.44 m (r)peaks peaks 36.51 r (m) 36.14 r (r) 36.83 g 29.4-29.7 29.4-29.629.4-29.6 n a) — — — h) — — — o a) — — — b) — — — Note: —: No distinctpeak was observed by the 13-CNMR measurement commonly conducted inExamples (accumulated number of times: about 5,000 times). Using1,1,2,2-tetrachloroethane-d2 as a solvent, the sample was heated anddissolved at 100° C. and then subjected to the measurement. The centerpeak of the triplet of tetrachloroethane by 13C-NMR had a shift value of73.89 ppm relative to TMS. Each peak shift value of a copolymer wascalculated relative to the center peak value of the triplet oftetrachloroethane being 73.89 ppm. a) mm, mmm or mmmm    b) rr, rrr orrrrr c) The peak shift value measured by using TMS as standard andchloroform-d as a solvent.

The alternating structural index λ, the isotactic diad index m of thestyrene-ethylene alternating structure and the isotactic diad index msof the head-to-tail styrene chain unit structure, of the copolymerobtained in each Example, were obtained in accordance with the aboveformulas (i), (ii) and (iii). The m and as values obtained in therespective Examples and Comparative Examples are shown in Table 4.

TABLE 4 St content Examples (mol %) Value 2 Value m Value ms Ex. 1 41.048 >0 >0.80 Ex. 2 53.8 50 >0.95 >0.80 Ex. 3 55.5 57 >0.95 >0.80 Ex. 472.9 20 >0.95 >0.80 Ex. 5 92.0 7 >0.95 >0.80 Ex. 6 15.5 8 >0.95 — Ex. 711.5 6 >0.95 — Ex. 8 7.0 4 >0.95 — Ex. 9 37.1 47 >0.95 — Ex. 10 47.159 >0.95 >0.80 Ex. 11 31.8 25 >0.95 — Ex. 12 38.9 30 >0.95 — Ex. 13 25.819 >0.95 — Ex. 14 27.9 18 >0.95 — Comp. 43.0 NM 0.65 — Ex. 1 Comp. 21.1NM 0.7 — Ex. 2 Comp. 49.8 NM 0.60 — Ex. 3 Comp. 13.0 NM 0.5 — Ex. 4Comp. 9.0 NM 0.5 — Ex. 5 Comp. <2 NM NM — Ex. 6 Comp. 9.5 NM 0.9 — Ex. 7NM: Not measured Note: —: No distinct peak attributable to a at leastthree head-to-tail styrene chain (a polystyrene chain), was observed bythe 13-CNMR measurement commonly carried out in Examples (accumulatednumber of times: about 5,000 times), and no calculation was accordinglypossible.

Further, the isotactic pentad index mmmm of styrene units, can beobtained by the following formula from the peak of the phenyl C1 carbonor the methylene carbon of the styrene chain structure by the 13C-NMRmeasurement.

mmmm=A(mmmm)/A(all)

A(mmmm): peak area of phenyl C1 carbon attributable to the mmmmstructure of the styrene chain

A(all): Sum of all peak areas of phenyl C1 carbon attributable to thestereoregularity.

Especially, in the case of the phenyl C1 carbon peak, a peakattributable to phenyl C1 of the copolymer structure is present in thevicinity of the mmmm peak of a head-to-tail styrene chain, but nosubstantial peak is observed in the vicinity of from 145.2 to 146.0 ppmwhich is the position where the peak attributable to an atarctic styrenechain or a syndiotactic styrene chain structure appears. Thus, mmmm isat least 0.2.

To show that the copolymer of the present invention can have acrystalline structure, the X-ray diffraction patterns of the copolymersobtained in Examples 10 and 14 are shown in FIG. 26. The samples weresubjected to suitable annealing treatment to improve the crystallinity,whereupon the measurements were carried out.

With a styrene-ethylene random copolymer of the present invention with astyrene content of at least 15 mol %, a diffraction peak from thecrystal structure attributable to the stereoregular styrene-ethylenealternating structure contained, was observed. When the styrene contentis less than about 15 mol %, a diffraction peak from a crystal structureof polyethylene will also be observed.

When a CGCT (constrained geometrical structure) type Ti complex,(tertiarybutylamide)dimethyl(tetramethyl-η5-cyclopetandienylsilanetitaniumdichloride or diphenylmethylene(fluorenyl)(cyclopentadienyl)zirconiumdichloride, is employed as the transition metal catalyst component, thestyrene-ethylene alternating structure in the resulting copolymer, hasno stereoregularity. Further, no head-to-tail styrene chain is observed.

When rac-ethylenebis(1-indenyl)zirconium dichloride is used as thetransition metal catalyst component, it is very difficult to increasethe styrene content to a level of at least 10 mol %, and the molecularweight of the resulting polymer is as low as 50,000 by weight averagemolecular weight (Mw). The copolymer with a styrene content of at least5 molt and less than 20 mol %, which has a weight average molecularweight of less than 60,000, is not useful as a practical polymer, sincethe physical properties such as breaking strength, etc. are poor. Whenthe same transition metal catalyst component is employed, as shown inComparative Example 10, homopolymerization of styrene does not proceed.It is impossible to form a styrene chain by this catalyst system.

When dimethylsilylenebis (2-methyl-4,5-benzindenyl)zirconium dichloridehaving a substituent pattern of the benzindenyl group which is differentfrom the transition metal compound as catalyst component forpolymerization of the present invention, is employed, a copolymer havinga styrene content of not more than 2 mol %, is obtained. Namely, when ametal complex having a substituent at the 2-position of the benzindenylgroup, is used, it is impossible to obtain a high styrene content.Further, no head-to-tail styrene chain is observed. When the sametransition metal catalyst component is used, as shown in ComparativeExample 9, no styrene polymer having stereoregularity can be obtained.An atarctic polystyrene produced in a small amount, is considered tohave been formed by cation or radical polymerization, according to knownliteratures. Thus, it is impossible to form a styrene chain by thiscatalyst system.

Preparation of Styrene-propylene Random Copolymers Example 15

An autoclave having a capacity of 1 lit. and equipped with a stirrer,was evacuated and substituted by nitrogen, and then 100 ml of styrene,40 ml of toluene, 5 mmol of triisobutylaluminum and 21 mmol, based on Alatom, of methylalumoxane (MMAO-3A, manufactured by TOSOH-AKZO K.K.) werecharged in this order. Then, the autoclave was cooled to −50° C. by dryice, and 1 mol of propylene gas was introduced. About 40 ml of a toluenesolution containing 21 μmol of a catalyst rac{BInd-C(Me)₂-BInd}ZrCl₂ and0.84 mmol of triisobutylaluminum, was introduced together with propylenegas, from a pressure resistant tank installed above the autoclave. Thedry ice bath was removed, and temperature was raised to 50° C. over aperiod of about 30 minutes and polymerization was carried out at 50° C.for one hour. After completion, the pressure was gradually released, andthe polymerization solution was post-treated in the same manner as inExample 1 to obtain 8.5 g of a polymer.

Examples 16 to 18

Polymerization and post treatment were carried out in the same manner asin Example 15 under the polymerization conditions shown in Table 5.

Comparative Example 8

Polymerization and post treatment were carried out in the same manner asin Example 15 under the conditions shown in Table 2, using, as acomplex, dimethylsilylenebis(2-methyl-4,5-benzindenyl)zirconiumdichloride.

Table 5 shows the polymerization conditions and the results.

Table 6 shows the styrene content and the molecular weight obtained byGPC, of the obtained polymer, and the results of the glass transitionpoint and melting point obtained by DSC.

FIGS. 27 and 28 show the GPC chart and the DSC spectrum of the copolymerobtained in Example 15.

In the GPC measurements of the polymers obtained in various Examples,the GPC curves obtained by different detectors (RI and UV) agree to eachother within an experimental error range, as shown in FIG. 27, althougha small shoulder is observed. This indicates that the compositionaldistribution of styrene is relatively uniform.

The glass transition point obtained by DSC being one, also indicates auniform composition of the copolymer.

Typical 13C-NMR charts of Examples 15, 17 and 18 are shown in FIGS. 29to 34.

Table 7 shows the results of 13C-NMR measurements,

The styrene-propylene copolymers of the present invention presentcomplex peak patterns by the 13C-NMR measurements, as shown in theFigures. This indicates that many different kinds of bond structureswere formed, for example, by formation of head-to-tail or tail-to-tailchains of propylene units one another, styrene units one another or apropylene unit and a styrene unit bonded to each other, or a structuresimilar to an ethylene chain due to a 1-3 bond of propylene.

However, among peaks of phenyl C1 carbon of a styrene unit (the carbonbonded to the main chain among six carbon atoms of a phenyl group), thepeak in the vicinity of 146.3 ppm is attributable to an isotacticpolystyrene chain, and the peak at 21.5 to 21.6 ppm of methyl carbon ina propylene unit, is attributable to an isotactic polypropylene chain.Namely, it is a copolymer which has a styrene chain structure, apropylene chain structure and a styrene-propylene bond structure,wherein the stereoregularity of the styrene chain structure and/or thepropylene chain structure is isotactic.

In the case of a propylene chain, the isotactic index (mm, mmm or mmmm)is obtained by comparing the area of an isotactic peak (mm, mmm or mmmm)of a methyl group in the vicinity of 21.5 ppm and the area of peaks ofall methyl groups. With respect to the propylene chain, the isotacticindex (mm, mmm or mmmm) is such that mm is at least 0.5, mmm is at least0.4, and mmmm is at least 0.2, although other peaks attributable to theabove-mentioned complex bond structures, are present in the vicinity.

In the case of a styrene chain, the isotactic index (mm, mmm or mmmm)can be obtained by comparing the area of the isotactic peak (mm, mmm ormmmm) of the phenyl C1 group in the vicinity of 146.3 ppm and the areaof all phenyl C1 peaks in the vicinity of from 145 to 146 ppm. Withrespect to the styrene chain, the isotactic index (mm, mmm or mmmm) issuch that mm is at least 0.5, mmm is at least 0.4, and mmmm is at least0.2.

When dimethylsilylenebis(2-methyl-4,5-bnzoindenyl)zirconium dichloridehaving a substituent pattern on a benzindenyl group which is differentfrom the transition metal catalyst component for polymerization of thepresent invention, is used, a mixture comprising an isotacticpolypropylene and an atarctic polystyrene, will be obtained.

Preparation of Isotactic Polystyrenes

Into a Shrenk tube having a capacity of 100 ml and equipped with amagnetic stirrer, which was evacuated and substituted by nitrogen, 10 mlof styrene and 0.84 mmol of triisobutylaluminum were charged. Further,0.8 μmol, based on Al, of methyl alumoxane (MMAO-3A, manufactured byTOSOH-AKZO K.K.) was added thereto, and 10 ml of a toluene solutioncontaining 1.5 μmol ofrac-dimethylmethylenebis(4,5-benz-1-indenyl)zirconium dichloride, wasadded thereto. The mixture was stirred at room temperature for 3 hoursand then put into a large excess amount of methanol acidified withhydrochloric acid to precipitate a polymer. The obtained polymer wasdried at 70° C. for 8 hours to obtain 1.5 g of a white powdery polymer.

Example 20

Polymerization and post treatment were carried out in the same manner asin Example 19 under the conditions shown in Table 3 by using, as acomplex, 4.6 μmol ofrac-dimethylmethylene(4,5-benz-1-indenyl)(1-indenyl)zirconiundichloride, to obtain 0.5 g of a white powdery polymer.

Comparative Example 9

Polymerization and post treatment were carried out in the same manner asin Example 13 under the conditions shown in Table 3, by changing thecomplex to rac-dimethylsilylbis(2-methyl-4,5-benzindenyl) zirconiumdichloride, another name; rac{2-Me-BInd-SiMe₂-2-Me-BInd}ZrCl₂, to obtain0.15 g of a white powdery polymer.

Comparative Example 10

Polymerization and post treatment were carried out in the same manner asin Example 19 under the conditions shown in Table 3 by changing thecomplex to rac-ethylenebis (1-indenyl) zirconium dichloride, anothername: rac{Ind-Et-Ind}ZrCl₂, whereby no polymer was obtained.

Table 8 shows the polymerization conditions and the results.

Table 9 shows the molecular weight of the obtained polymer determined byGPC, and the results of the glass transition point and melting pointdetermined by DSC.

The 13C-NMR chart of the obtained polymer is shown in FIG. 35, the DSCchart is shown in FIG. 36, and the X-ray diffraction pattern is shown inFIG. 37.

The peak shift value of the 13C-NMR obtained by using the center peak(73.89 ppm) of the triplet of 1,1,2,2-tetrachloroethane-d2, as standard,was as follows.

Methine Methylene Phenyl C1 carbon carbon carbon EXAMPLE 19 40.7 43.0146.3 EXAMPLE 20 40.7 43.0 146.3

The melting point obtained by DSC was 222° C., and from the results ofthe X-ray diffraction, it is evident that the obtained copolymer was anisotactic polystyrene.

The meso pentad index (mmmm) obtained from the peak of the phenyl C1carbon of the isotactic polystyrene obtained in Example 19, was at least0.90. In the case of Comparative Example 9 whereinrac-dimethylsilylenebis(2-methyl-4,5-benzindenyl)zirconium dichloridewas used, a very small amount of atarctic polystyrene was obtained, butthis is considered to have been formed by radical polymerization orcation polymerization by the coexisting methylalumoxane or analkylaluminum included therein.

In the case of Comparative Example 10 whereinrac-ethylenebis(1-indenyl)zirconium dichloride was used, no polymer wasobtained.

Preparation of Styrene-ethylene Alternating Copolymers Example 21

Polymerization was carried out by using an autoclave having a capacityof 1 lit. and equipped with a stirrer.

240 ml of toluene and 240 ml of styrene were charged, and the innertemperature was raised to 50° C. About 80 lit of nitrogen was introducedfor bubbling to purge the interior of the system. Then, the autoclavewas cooled by immersing it in an ice bath. Then, 8.4 mmol oftriisobutylaluminum and 8.4 mmol, based On A1, of methylalumoxane(PMAO-S, manufactured by TOSOH-AKZO K.K.) were added thereto. Ethylenewas immediately introduced, and after the pressure was stabilized at 0.2MPa (1 kg/cm²G), about 30 ml of a toluene solution containing 6kg/cm²mol of a catalyst obtained in “Preparation A”,rac-dimethylmethylene bis(4,5-benz-1-indenyl)zirconium dichloride and0.84 mmol of triisobutylaluminum, was added to the autoclave from acatalyst tank installed above the autoclave. Polymerization was carriedout for 6 hours while maintaining the inner temperature at a level of 2to 6° C. and the ethylene pressure at a level of 0.2 MPa(1 kg/cm²G).During the polymerization, the rate of consumption of ethylene wasmonitored by a flow rate accumulator, so that the progress of thepolymerization reaction was monitored. Upon expiration of 6 hours,polymerization was substantially in progress without no deactivation.The ethylene pressure was released, and the obtained polymerizationsolution was gradually put into an excess amount of methanol toprecipitate the formed polymer. The product was dried for about 10 hoursunder reduced pressure at 80° C. until no weight change was any longerobserved, to obtain 39 g of a polymer.

Example 22

Polymerization and post treatment was carried out in the same manner asin Example 21 except that the complex was used in an amount of 8.4 μmoland polymerization was carried out by immersing the autoclave in acooling bath of −20° C. to maintain the inner temperature at −16° C., toobtain 1.5 g of a polymer. This polymer contained atarctic polystyrenehomopolymer, and it was further subjected to extraction treatment withboiling acetone, whereby 0.7 g of a white powder polymer was obtained asan insoluble fraction in boiling acetone.

Comparative Example 11

Polymerization and post treatment were carried out in the same manner asin Example 21 under the conditions shown in Table 4, by using, as thecatalyst, ethylenebisindenylzirconium dichloride. As a result, 14 g of apolymer was obtained.

The obtained copolymer was a mixture of atarctic polystyrene and thecopolymer, and it was extracted with boiling acetone to obtain 8 g of awhite polymer as an insoluble fraction in boiling acetone.

The polymerization conditions and the polymerization results in therespective Examples and Comparative Examples are shown in Table 10.

Further, the molecular weights, the molecular weight distributions, themelting points and the glass transition temperatures of the copolymersobtained in the respective Examples and Comparative Examples are shownin Table 11, and the 13C-NMR peak shift values are shown in Table 12.

As an example of the copolymer obtainable by the present invention, the1H-NMR of the copolymer obtained in Example 21 is shown in FIG. 38, andthe 13C-NMR spectrum is shown in FIGS. 39 and 40.

The aromatic vinyl compound-ethylene alternating copolymer obtained bythe present invention, is an aromatic vinyl compound-ethylenealternating copolymer characterized in that the stereoregularity ofphenyl groups in the alternating structure of ethylene and the aromaticvinyl compound, is represented by an isotactic diad index m of largerthan 0.95, and the alternating structure index λ of the followingformula (i) is at least 70.

The alternating index λ is given by the following formula (i):

λ=A3/A2×100  (i)

Here, A3 is the sum of areas of three peaks a, b and c attributable tothe carbons of aromatic vinyl compound-ethylene alternating structure ofthe following formula (5′), as obtained by the 13C-NMR measurements, andA2 is the sum of areas of peaks attributable to the main chain methyleneand methine carbon, as observed within a range of from 0 to 50 ppm by13C-NMR using TMS as standard.

wherein Ph is an aromatic group such as a phenyl group, and x is aninteger of at least 2, representing the number of repeating units,

wherein Ph is an aromatic group such as a phenyl group, and x is aninteger of at least 2, representing the number of repeating units.

Namely, it has a structure represented by the following formula whichcomprises methine carbon atoms bonded to the Ph groups and threemethylene carbon atoms sandwiched therebetween. (For the simplicity,hydrogen atoms are omitted.)

The isotactic diad (meso diad) index m of the alternating copolymerstructure of ethylene and styrene, can be obtained by the above formula(ii).

Further, the alternating structure index λ obtained by the above formulais shown in Table 13.

The isotactic diad index m of the styrene unit-ethylene unit alternatingstructure of the copolymer obtained in each Example, was obtained by theabove formula. Table 13 shows m obtained in each Example or ComparativeExample.

As an example of the copolymer obtainable by the present invention, theGPC chart of the copolymer obtained in Example 21 is shown in FIG. 41.

As an example of the copolymer obtainable by the present invention, theDSC chart of the copolymer obtained in Example 22 (measured afterquenching with liquid nitrogen from a molten state, the temperatureraising rate; 20° C./min) is shown in FIG. 42.

It is evident from FIG. 42 that the copolymer of the present inventionhas a high melting point and a high crystallization speed.

As an example of the copolymer obtainable by the present invention, theX-ray diffraction chart of the copolymer obtained in Example 21 is shownin FIG. 43.

As shown in Comparative Example 11, in a case whereethylenebisindenylzirconium dichloride is used as a metal complex, thestyrene content can not be increased under a practical polymerizationtemperature condition of at least −20° C., whereby it is impossible toobtain a copolymer having a high alternating nature.

TEST EXAMPLES Preparation D of Transition Metal Compound as CatalystComponent

Rac-dimethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconium dichloride(rac{CpPhen-CMe₂-CpPhen}ZrCl₂), was prepared as follows. Here, CpPhenrepresents cyclopentadienyl[c]phenanthryl.

1H or 3H-cyclopenta[c]phenanthrene was prepared in accordance with themethod disclosed in Organometallics, 16, 3413, 1997.

D-1 Isopropylidenebis(cyclopenta)[c]phenanthrene)

In an Ar atmosphere, 32 mmol of 1H or 3H-cyclopenta[c]phenanthrene wasadded to 40 ml of dimethoxyethane having 3.0 g of potassium hydroxidesuspended therein, and the mixture was stirred at room temperature for30 minutes. Then, 15 mmol of acetone was added thereto, followed bystirring at 60° C. for 2 hours. A 10% phosphoric acid aqueous solutionwas added for neutralization, and the mixture was extracted withmethylene chloride. The organic layer was washed with water and dried,and methylene chloride was distilled off. By recrystallization from amethylene chloride-diethyl ether solution, 1.5 g ofisopropylidenebis(cyclopenta[c]phenanthrene) was obtained as whitecrystals.

By the 1H-NMR spectrum measurement, it had peaks at 1.93 ppm (6H,s),4.20 ppm (4H,d), 6.89 ppm (2H,t), 7.5 to 7.9 ppm (14H,m) and 8.91 ppm(2H,d), The measurement was carried out by using TMS as standard andCDCl₃ as the solvent.

D-3 Preparation ofrac-dimethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconium dichloride

In an Ar stream, 2.0 mmol ofisopropylidenebis(cyclopenta[c]phenanthrene) and 2.0 mmol of zirconiumtetrakisdimethylamide{Zr(NMe₂)₄} were charged together with 20 ml oftoluene and stirred for 7 hours under reflux. Toluene was distilled offunder reduced pressure, and 50 ml of methylene chloride was addedthereto. The mixture was cooled to −50° C. Then, 4.0 mmol ofdimethylamine hydrochloride was gradually added, and the temperature wasslowly raised to room temperature, and stirring was further conductedfor 2 hours. After distilling off the solvent, the obtained solid waswashed with pentane and then with a small amount of methylene chlorideto remove meso-isomer and ligand, to obtain 0.36 g ofrac-dimethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconium dichlorideas yellow orange crystals. From the 1H-NMR spectrum, it was found tohave peaks at 2.55 ppm (6H,s), 6.49 ppm (2H,d), 7.55-8.02 ppm (16H,m),and 8.82 ppm (2H,d).

The measurement was carried out by using TMS as standard and CDCl₃ as asolvent.

Preparation of Styrene-ethylene Random Copolymers Example 23

Polymerization and post treatment were carried out in the same manner asin Example 2 under the conditions shown in Table 14, by using, as acatalyst rac-dimethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconiumdichloride which is the catalyst obtained in “Preparation D oftransition metal compound as catalyst component”.

As a result, 910 g of a polymer was obtained. The styrene content was57.0 mol %, the molecular weight (Mw) was 279,000, the molecular weightdistribution (Mw/Mn) was 2.0, and the glass transition point was 40° C.

As a result of the 13C-NMR measurement, a peak was observed which isattributable to two or more head-to-tail styrene chain structure.

The 13C-NMR spectra are shown in FIGS. 44, 45 and 46. The peak shiftvalues of the 13C-NMR spectra are shown in Table 15.

The stereoregularity of the styrene-ethylene alternating structure wasisotactic, and m was at least 0.95, ms was at least 0.80, and thealternating structure index λ was 30. When this complex is used as acatalyst component, it is possible to obtain a copolymer having a highrandom nature (low alternating nature) under the conditions of Examples.

Example 24

Polymerization and post treatment were carried out n the same manner asin Example 19 under the conditions shown in Table 14, by using, as acatalyst, rac-dimethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconiumdichloride which is the catalyst obtained in “Preparation D oftransition metal compound as catalyst component”. As a result, 1.8 g ofa polymer was obtained.

The molecular weight (Mw) was 208,000, the molecular weight distribution(Mw/Mn) was 1.7, and the melting point was 225° C. The peak shift valuesof 13C-NMR obtained by using the center peak (73.89 ppm) of the tripletof 1,1,2,2-tetrachloroethane-d2 as standard, were as follows.

Methine Methylene Phenyl C1 carbon carbon carbon EXAMPLE 24 40.7 43.0146.3

The meso pentad index (mmmm) obtained from the phenyl C1 carbon peak wasat least 0.95.

When rac-dimethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconiumdichloride is used as a transition metal catalyst component, it ispossible to produce a styrene-ethylene random copolymer having a highmolecular weight and an isotactic polystyrene under very high catalyticactivities.

REFERENCE EXAMPLE 1 Preparation of polyethylene

Into an autoclave having a capacity of 120 ml and equipped with amagnetic stirrer, which was evacuated and substituted by ethylene, 20 mlof toluene and 8.4 μmol, based on Al atom, of methylalumoxane (MMAO-3A,manufactured by TOSOH AKZO K.K.) were charged.

The inner temperature was raised to 50° C., and 16 ml of a toluenesolution containing 1.0 μmol of rac{BInd-C(Me)₂-BInd}ZrCl₂ and 0.84 mmolof triisobutylaluminum, was quickly charged by a syringe with magneticstirring, and ethylene was immediately introduced to raise the pressureto a total pressure of 0.6 MPa (5 kg/cm²G). Polymerization was carriedout for 10 minutes while maintaining the pressure at a level of 5kg/cm²G. The polymerization solution was put into a large excess amountof dilute hydrochloric acid/methanol liquid to precipitate a polymer,which was dried under vacuum at 70° C. for 8 hours. As a result, 1.7 gof a polyethylene was obtained, As a result of the DSC measurement, themelting point was 130° C.

TABLE 5 Amount Amount Amount Amount of Cocata- of of of Productivity Stcontent Cata- catalyst lyst toluene styrene propylene PTE PTI Yield(g/mol-cata- (mol %) Example lyst (mol) (mmol) (ml) (ml) (mol) (° C.)(hr) (g) lyst)/10^(b) (%) Ex. 15 A 21 21 80 100 1.0 −50 1.5 8.5 0.4 55.650 Ex. 16 A 8.4 21 80 100 1.0 50 1 2.3 0.27 42.2 Ex. 17 A 8.4 21 160 202.0 20˜38 1 23.3 2.8 3.9 Ex. 18 A 8.4 21 80 100 0.25 50 1 1.9 0.23 72.5Comp. F 21 21 80 100 1.0 50 1 0.4 0.02 Ex. 8 (0.3) Atarctic PS 100 (0.1)Isotactic PP ˜0 Transition metals used as catalysts A:rac-dimethylmethylenebis(4,5-benz-1-indenyl) zirconium dichloride F:rac-dimethylsilylenebis (2,methyl-4,5-benz-1-indenyl) zirconiumdichloride PTE: Polymerization temperature PTI: Polymerization time

TABLE 8 Amount of Cocata- Amount Amount Productivity Cata- catalyst lystof of PTE PTI Yield (g/mol-cata- Example lyst (mol) (mmol) toluenestyrene (° C.) (hr) (g) lyst)/10^(b) Ex. 19 A 1.5 8.4 10 10 23 3 1.5 1.0Ex. 20 B 4.6 8.4 10 10 23 3 0.5 0.1 Comp. F 3.6 8.4 16 10 23 3 0.15 0.04Ex. 9 Comp. G 8.4 8.4 16 10 23 3 0 0 Ex. 10 Transition metals used ascatalysts A: rac-dimethylmethylenebis(4,5-benz-1-indenyl) zirconiumdichloride B: rac-dimethylmethylenebis(1-indenyl) (4,5-benz-1-indenyl)zirconium dichloride F: rac-dimethylsilylenebis(2,methyl-4,5-benz-1-indenyl) zirconium dichloride G:rac-ethylenebis(1-indenyl) zirconium dichloride PTE: Polymerizationtemperature PTI: Polymerization time

TABLE 6 Glass transi- St tion Melting content Mw Mn temp. point Examples(mol %) /10* /10* Mw/Mn (° C.) (° C.) Ex. 15 55.6 2.0 1.2 1.7 35 * Ex.16 42.2 1.6 0.9 1.8 35 * Ex. 17 3.9 1.7 1.0 1.0 −18 118 Ex. 18 72.5 1.60.9 1.7 75 * Comp. 100 2.1 0.7 3.0 — — Ex. 8 ˜0 11.2 4.6 2.5 — — *: Nomelting point was observed.

TABLE 9 Glass transi- tion Melting Mw/ Mn/ temp. point Examples 10⁴ 10⁴Mw/Mn (° C.) (° C.) Ex. 18 3.6 1.9 1.9 85 222 Ex. 19 2.0 1.1 1.9 85 220Comp. 1.0 0.6 1.7 88 * Ex. 9 Comp. — — — — — Ex. 10 *No melting pointwas observed.

TABLE 7 Main peak shift values (ppm) by 13C-NMR, obtained by using1,1,2,2-tetrachloroethane d2 as a solvent Attribution Ex. 15 Ex. 16 Ex.17 Ex. 18 Propylene 21.54 21.54 21.52 21.6 Unit methyl Propylene 27.4227.42 28.05 Not Unit methylene 27.65 27.63 distinct Propylene 45.3 45.2845.70 Not Unit methine distinct Styrene 40.42 40.4 Not 40.53 unitmethine -40.50 -40.5 distinct Styrene 42.8—43.2 42.5—43.2 Not 42.95 Unitmethylene distinct Styrene 113.68 143.67 144.42 145.73 Unit 146.30146.31 146.63 146.31 Phenyl C1 146.61 146.60 Note: —: No distinct peakwas observed by the 13-CNMR measurement commonly conducted in Examples(accumulated number of times: about 5,000 times). Using1,1,2.2-tetrachloroethane-d2 as a solvent, the sample was heated anddissolved at 100° C. and then subjected to the measurement. The centerpeak of the triplet of tetrachloroethane by 13C-NMR had a shift value of73.89 ppm relative to TMS. Each peak shift value of a copolymer wascalculated relative to the center peak value of the triplet oftetrachloroethane being 73.89 ppm.

TABLE 10 Amount Cocata- Amount Amount Product- of lyst of of Ethyleneivity Cata- catalyst (mmol) toluene styrene pressure PTE PTI Yield(g/mol-cata- St content Examples lyst (mol) MAO (ml) (ml) MPa (° C.)(hr) (g) lyst)/10^(b) (mol %) Ex. 21 A 6 8.4 240 240 0.2 2˜6 6 39 6.553.3 Ex. 22 A 8.4 8.4 240 240 0.2 −16 6 1.5 0.2 (0.7) (0.1) (50.0) Comp.G 21 21 80 400 0.2 2˜6 6 14 0.7 Ex. 11 (8) (0.4) (21.0) In the bracket (), a boiling acetone-insoluble content (styrene-ethylene copolymer) isindicated. Transition metals used as catalysts A:rac-dimethylmethylenebis(4,5-benz-1-indenyl) zirconium dichloride G:rac-ethylenebis(1-indenyl) zirconium dichloride PTE: Polymerizationtemperature PTI: Polymerization time

TABLE 14 Amount Cocata- Amount Amount Product- of lyst of of Ethyleneivity Cata- catalyst (mmol) solvent styrene pressure PTE PTI Yield(g/mol-cata- St content Examples lyst (mol) MAO (ml) (ml) MPa (° C.)(hr) (g) lyst)/10^(b) (mol %) Ex. 23 H 21 84 T 800 4000 0.2 50 5 91043.3 57.0 Ex. 24 H 1.0 8.4 T 16 10 — 23 3 1.8 1.8 100 T: TolueneTransition metals used as catalysts H: dimethylmethylenebis(3-cyclopenta(c)phenanthryl)zirconium dichloride PTE: Polymerizationtemperature PTI: Polymerization time

TABLE 11 Glass transi- St tion Melting content Mw Mn temp. pointExamples (mol %) /10⁴ /10⁴ Mw/Mn (° C.) (° C.) Ex. 20 53.3 31.7 23.7 1.827 134 Ex. 21* 50.0 2.0 1.1 1.8 22 158 Comp. 27.0 2.4 1.3 1.8 −2 120*Boiling acetone-insoluble fraction (styrene-ethylene copolymer)

TABLE 12 Main peak shift values (ppm) by 13C-NMR, obtained by using1,1,2,2-tetrachloroethane d2 as a solvent Attribu- Ex. 22 Comp. Ex. 11tion Ex. 21 *1 *1 c m 25.12 25.12 25.11 r — — (25.32) *2 Small peak a mm45.33 45.21 45.29 mr — — — rr — — — b m (m) 36.46 36.46 36.44 m (r) — —Not analyzable r (m) — — as peaks r (r) — — overlapped with Et blockpeaks *1: Boiling acetone-insoluble fraction *2: —: No distinct peakattributable to at least three head-to-tail styrene chain (a polystyrenechain), was observed by the 13-CNMR measurement commonly carried out inExamples (accumulated number of times: about 5,000 times), and nocalculation was accordingly possible.

TABLE 13 Value Examples λ Value m Ex. 21 78 1.0 Ex. 22 *1 80 1.0 Comp.35 0.90 Ex. 11 *1 *1: Boiling acetone-insoluble fraction

TABLE 15 Main peak shift values (ppm) by 13C-NMR, obtained by using1,1,2,2-tetrachloroethane d2 as a solvent Attribu- tion Ex. 23 c m 25.12r — a mm 45.18-45.27 mr — rr — b m (m) 36.46 m (r) — r (m) — r (r) — g29.3-29.7 n mmmm 40.8-40.9 rrrr — o mmmm 43.3-43.6 rrrr j 42.8-42.9 k43.9-44.1 Note: —: No distinct peak was observed by the 13-CNMRmeasurement commonly conducted in Examples (accumulated number of times:about 5,000 times) Using 1,1,2,2-tetrachloroethane-d2 as a solvent, thesample was heated and dissolved at 100° C. and then subjected to themeasurement. The center peak of the triplet of tetrachloroethane by13C-NMR had a shift value of 73.89 ppm relative to TMS. Each peak shiftvalue of a copolymer was calculated relative to the center peak value ofthe triplet of tetrachloroethane being 73.89 ppm.

Example 25 Preparation of Styrene-ethylene Random Copolymer

Rac-dimethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconium dichlorideprepared by Preparation D of the above transition metal catalystcomponent was used as a catalyst, and polymerization was carried outunder the conditions shown in the following Table 16.

The polymerization was carried out by using an autoclave of 10 lequipped with a stirrer and a jacket for heating and cooling.

800 ml of dehydrated toluene and 4,000 ml of dehydrated styrene werecharged therein, and the resultant mixture was heat-stirred at an innertemperature of 50° C. The reaction system was purged by bubbling about100 l of nitrogen, and 8.4 mmol of triisobutyl aluminum and 84 mmol (interms of Al) of methyl alumoxane (MMAO-3A manufactured by TOSOH AKZOCo.) were added thereto. The content of the autoclave was substituted byimmediately introducing ethylene, and after stably fixing to a pressureof 0.1 MPa (0 kg/cm²G, atmospheric pressure), about 50 ml of toluenesolution having 21 μmol ofrac-dinethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconium dichloride(catalyst obtained in Preparation D of the above transition metalcatalyst component) and 0.84 mmol of triisobutyl aluminum dissolved wasadded to the autoclave from a catalyst tank equipped above theautoclave. By maintaining an internal temperature of 50° C. and apressure of 0.1 MPa, polymerization was carried out for 2.5 hours. Afterpolymerization, the polymerization liquid thus obtained was graduallyadded in a small amount into an excess amount of methanol vigorouslystirred to precipitate a polymer. Under a reduced pressure, the reactionproduct was dried at 60° C. until no weight change was observed, therebyobtaining 504 g of a polymer.

Examples 26 to 31 (except for Example 27)

The same polymerization procedure as in Example 25 was carried out underthe conditions shown in following Table 16.

PMAO or MMAO manufactured by TOSOH-AXZO Co. was used.

Example 27

Polymerization was carried out by using a polymerization tank having avolume of 150 l, equipped with a stirrer and a jacket for heating andcooling.

36 l of dehydrated cyclohexane and 36 l of dehydrated styrene werecharged, and the resultant mixture was heat-stirred at an internaltemperature of about 500° C. 84 mmol of triisobutyl aluminum and 840mmol (in terms of Al) of methyl alumoxane (MMAO-3A manufactured byTOSOH-AKZO Co.) were added thereto. After immediately introducingethylene and after stably fixing a pressure to 0.3 MPa (2 kg/cm²G), froma catalyst tank equipped above the polymerization tank, about 100 ml oftoluene solution having 105 μmol ofrac-dimethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconium dichloride(the above transition metal catalyst component D) and 10 mmol oftriisobutyl aluminum dissolved was added into the polymerization tank.Thereafter, by maintaining a temperature of about 50° C. and a pressureof 0.2 MPa, polymerization was carried out for 3.0 hours.

After polymerization, the polymerization liquid thus obtained wasdegassed, and was treated in accordance with crumb-forming method asillustrated below, thereby recovering a polymer.

The polymerization liquid was diluted with 72 l of cyclohexane, and theresultant mixture was charged into 300 l water heated at 85° C. andvigorously stirred, containing a dispersant (Pluronic: tradename) over 2hours. Thereafter, the mixture was stirred at 97° C. for 1 hour, and hotwater containing crumb was charged into cooled water to recover thecrumb. The crumb thus obtained was dried in air at 50° C., and was thendegassed under vacuum at 60° C. to obtain 9.5 kg of a satisfactorypolymer of crumb-shape having a size of about several mm.

Preparation E of Transition Metal Catalyst Component

Rac-dimethylmethylene(3-cyclopenta[c]phenanthryl)(1-indenyl)zirconiumdichloride (another name: rac{CpPhen-CMe₂-Ind}ZrCl₂) was prepared in thefollowing manner. CpPhen represents cyclopenta[c]phenanthryl),

E-1 Preparation of 1,1-isopropylidene-3-cyclopenta[c]phenanthrene

Preparation of 1,1-isopropylidene-3-cyclopenta[c]phenanthrene wascarried out with reference to the preparation of 6,6-diphenylfulvene inaccordance with the description of Can. J. Chem., vol. 62, 1751 (1984).However, as starting materials, acetone was used in place ofbenzophenone and 1H or 3H-cyclopenta[c]phenanthrene was used in place ofcyclopentadiene.

E-2 Preparation of isopropylidene(1-indene)3-cyclopenta[c]phenanthrene)

In an Ar atmosphere, 14 mmol of indene was dissolved in 50 ml of THF,and an equivalent amount of BuLi was added thereto at 0° C., and theresultant mixture was stirred for about 10 hours. 20 ml of THF having 14mmol of 1,1-isopropylidene-3-cyclopenta[c]phenanthrene dissolved wasadded thereto, and the mixture was stirred at 0° C. to room temperatureovernight. 50 ml of water and 100 ml of diethyl ether were addedthereto, and the mixture was shaked to separate an organic phase, andthe organic phase thus separated was washed with saturated salt waterand was then dried with sodium sulfate, and the solvent was distilledoff under reduced pressure. The product thus obtained was furtherpurified by a column to obtain isopropylidene(1-indene)(3-clopenta[c]phenanthrene). The yield was 32%.

3 Preparation ofrac-dimethylmethylene(3-cyclopenta[c]phenanthryl)(1-indenyl)zirconiumdichloride

The aimed product was prepared in the same manner s in Preparation D-3of rac-dimethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconiumdichloride. The obtained product was yellow orange powder and the yieldwas 28%.

According to the 1H-NMR spectrum measurement, it was found to have peaksat 2.43 ppm (3H,s), 2.47 ppm (3H,s), 6.28 ppm (1H,d), 6.36 ppm (1H,d),6.71(1H,dd), 7.08-7,97 ppm (12H,m) and 8.88 ppm (1H,d).

Chloroform H peak in chloroform-d was observed at 7.254 ppm, and thepeak of impurity toluene was observed at 2.3499 ppm. The measurement wascarried out using CDCl₃ as a solvent.

Example 32

By using 8.4 μmol of rac{CpPhen-CMe₂-Ind}ZrCl₂ obtained in Preparation Eof transition metal catalyst component as a catalyst, polymerization wascarried out under the conditions shown in the following Table 16.

Table 16 shows the results and the polymerization conditions ofrespective Examples.

TABLE 16 Polymer- Product- Catalyst Cocatalyst Solvent Styrene Ethyleneization Polymer- ivity St amount (mmol) amount amount pressure pressureization Yield (g/mol- content Examples Catalyst (μmol) MAO (ml) (ml)(MPa) (° C.) time (h) (g) cat)/10⁶ (mol %) Example 25 D 21 M84  T8004000 0.1 50 2.5 504 24.0 60.0 Example 26 D 84 M84  T800 4000 0.08 50 4.0740 8.8 70.0 9.5 Example 27 D .105 M840 C36L 36L 0.3 50 3.0 kg 91 53.5Example 26 D 8.4 P8.4 T2000 2800 1.1 70 2.0 570 45.0 Example 29 D 8.4P21 T4000  800 1.1- 70-92 0.5 675 80 9.1 0.5 Example 30 D 8.4 P8.4 T4000800 1.1- 70-79 0.5 553 66 5.5 0.9 Example 31 D 8.4 P8.4 T4000  800 1.150-62 0.5 543 65 4.3 Example 32 E 8.4 P8.4 T4000  800 1.1 70 3.0 470 567.0 P; PMAO, M; MMAO, T; toluene, C; cyclohexane Transition metalcompounds used as catalysts: D: rac-dimethyl methylenebis(3-cyclopenta[c]phenanthryl) zirconium dichloride E: rac-dimethylmethylene (3-cyclopenta[c]phenanthryl)(1-indenyl) zirconium dichloride

Table 17 shows styrene contents, molecular weights measured by GPC,glass transition points measured by DSC and melting points of thepolymers obtained.

Melting point was measured with 10 mg of a sample treated at 60 to 70°C. for about 10 hours in a nitrogen stream at a temperature raising rateof 20° C./min from room temperature to 250° C. to confirm presence orabsence of melting point between 70° C. and 250° C. (1st-run). Thesample was maintained at 250° C. for 10 minutes, and was then quenchedwith liquid nitrogen, and was then heated from −100° C. to 280° C. at atemperature raising rate of 10° C./min to measure glass transition point(Tg) (2nd-run).

TABLE 17 Glass St transition content temperature Melting Examples (mol%) Mw/10⁴ Mw/Mn (° C.) point (° C.) Example 25 60.0 28.4 2.4 58 Meltingpoint was not observed. Example 26 70.0 24.6 2.2 56 Melting point wasnot observed. Example 27 53.5 23.0 2.2 49 Melting point was notobserved. Example 28 45.0 18.0 22 22 Melting point was not observed.Example 29 9.1 12.1 2.2 −21  93 Example 30 5.5 10.0 2.1 −26 103 Example31 4.3 11.7 2.1 24 105 Example 32 7.0 11.6 2.0 −24  93

FIGS. 47 and 48 illustrate a GPC chart and a DSC chart of the copolymerobtained in Example 25 as a typical example of the styrene-ethylenecopolymer of the present invention. In the GPC measurement of a polymerobtained in each Example, the GPC curves obtained by different detectors(RI and UV) correspond to each other within an error range of experimentas illustrated in FIG. 47, and this fact proves that the copolymerobtained has quite uniform composition distribution.

Also, the glass transition point determined by DSC is one as illustratedin Table 17, and this fact also proves that the copolymer has uniformcomposition.

Each copolymer obtained in each Example was press-molded at 180° C., andwas subjected to annealing at 50° C. for 1 week, and was subjected tox-ray diffraction analysis, the results of which are shown in thefollowing Table 18. With regard to each copolymer of each Example of thepresent invention, a diffraction peak derived from ethylene-styrenealternating structure was not observed. However, with regard to acopolymer having a styrene content of about at most 15 mol %, adiffraction peak derived from ethylene chain structure (polyethylene)crystal was observed. On the other hand, with regard to each copolymerof each Comparative Example, a diffraction peak derived fromethylene-styrene alternating structure was clearly observed.

TABLE 18 St content Examples (mol %) Results of X-ray diffractionExample 25 60.0 No diffraction peak was observed. Example 26 70.0 Nodiffraction peak was observed. Example 27 53.5 No diffraction peak wasobserved. Example 28 45.0 No diffraction peak was observed. Diffractionpeak derived from polyethylene Example 29 9.1 crystal was observed.Example 30 5.5 Diffraction peak derived from polyethylene crystal wasobserved. Example 31 4.3 Diffraction peak derived from polyethylenecrystal was observed. Example 32 7.0 Diffraction peak derived frompolyethylene crystal was observed.

FIG. 49 illustrates a diffraction spectrum of the annealed copolymer ofExample 25, and FIG. 50 illustrates a diffraction spectrum of acopolymer having a crystal structure derived from ethylene-styrenealternating structure.

Table 19 shows physical properties of a copolymer sample obtained inExample 25 and a copolymer sample annealed at 50° C. for 1 week. Theannealing treatment did not cause any substantial change in mechanicalproperties, hardness, transparency and the like. Also, it is evidentthat the copolymer of the present invention has a high transparency anda low haze before and after annealing treatment. The copolymer of thepresent invention is a copolymer in which a change in physicalproperties as a lapse of time is very small.

Tensile modulus of elasticity, tensile breaking extension and tensilestrength at break were measured in accordance with JIS K 7113 by moldingto form a sheet having a thickness of 1 mm by heat-press method (200°C., 4 minutes, 50 kg/cm²G) and punching to prepare a sample of No. 2dumbbell-like shape.

Total light transmittance and haze were measured in accordance with JISK-7105 by using a sample of 1 mm sheet formed in the same manner asmentioned above and using a turbidity meter NDH2000 manufactured byNihon Denshoku Kogyo K.K.

Surface hardness (Shore A, D hardness) was measured in accordance withJIS K-7215.

TABLE 19 Copolymer prepared Copolymer prepared in Example 25 in Example(before annealing) 25 (after annealing) Breaking elongation (%) 6 6Yield strength (MPa) Yield point was Yield point was not observed. notobserved. Breaking point strength (MPa) 31.5 32.8 Tensile elasticmodulus (MPa) 804 907 Haze (%) 14.5 14.1 Total light transmittance (%)85.2 85.9 Hardness (shore-D) 63 61 Hardness (shore-A) 98 98

FIGS. 51 and 52 illustrate 13C-NMR spectra of polymers obtained inExamples 26 and 29.

Peak shift values (13C-NMR) derived from 2 or more head-to-tail styrenechains of copolymers obtained in respective Examples are illustrated inTable 20.

A structure index λ value of a copolymer obtained in each Example wasdetermined in accordance with the above formula (i). λ values and mvalues obtained with regard to each Example are shown in the followingTable 21.

Isotactic diad (mesodiad) index m of alternating structure wasdetermined in accordance with the above formula (ii).

By carrying out 13C-NMR measurement, a peak derived from head-to-tailstyrene chain structure can be clearly observed.

A ratio x of an aromatic vinyl compound unit amount (derived fromhead-to-tail chain structure of aromatic vinyl compound unit containedin a copolymer) to the total aromatic vinyl compound unit amount wasdetermined by the following formula.

x=xa/xb×100  (iv)

In the above formula, xa is a total value of peak areas derived frommain chain methine carbons of head-to-tail chain structures of two ormore aromatic vinyl compound units. For example, in the 13C-NMRmeasurement based on TMS, a total value of peak (n) observed at40.4-41.0 ppm and peak (j) observed at 42.3-44.6 ppm. xb is a totalvalue of peak areas derived from main chain methine carbons of totalaromatic vinyl compound units contained in a copolyner.

The following Table 21 shows a x value of a copolymer of each Example.

TABLE 20 Main peak shift value (ppm) by 13C-NMR usingtetrachloroethane-d as a solvent Attribution Example 1 Example 2 Example3 Example 4 Example 5 Example 6 Example 7 Example 8 n Note 1) Note 240.4-40.7 40.6-40.9 40.5-40.8 40.5-40.9 — — — — Note 3 — — — — — — — — oNote 2 43.0-43.4 43.0-43.5 43.0-43.6 43.1-43.5 — — — — Note 3 — — — — —— — — j 42.3-42.7 42.4-42.7 42.6-42.7 427-42.9 43.1, 43.4 42.9 43.3 — k43.7-44.1 43.8-44.1 43.8-44.3 43.9-44.4 44.2 44.3 43.9-44.4 — Note 1):Clear peaks could not be observed by 13C-NMR measurement (about 10,000times integration) conducting usual determination of Examples. Note 2)m, mm, mmm or mmmm, Note 3) r, rr, rrr or rrrr

Sample was measured by heat-dissolving at about 100° C. and usingtetrachloroethane-d as a solvent.

The center peak of triplet 13C-NMR peak of tetrachloroethane showed ashift value of 73.89 ppm to TMS. Each peak shift value of coplymers wasdetermined by taking the triplet center peak value of tetrachloroethaneas 73.89 ppm.

TABLE 21 St content Examples (mol %) λ value m value x value Example 2560.0 20 >0.95 about 60 Example 26 70.0 18 >0.95 about 70 Example 27 53.533 >0.95 29 Example 28 45.0 30 >0.95 23 Example 29 9.1  4 >0.95  5Example 30 5.5  3 >0.95  3 Example 31 4.3  2 >0.95  2 Example 32 7.0 3 >0.95 Unmeasured

In the 13C-NMR measurement, peaks derived from two or more head-to-tailstyrene chain structures were observed. The aromatic vinylcompound-ethylene copolymer of the present invention provides a clearpeak derived from head-to-tail styrene chain structure, which can beobserved even by usual 13C-NMR measurement (about 20,000 timesintegration), even when a styrene content is less than 10 mol %.

In the present Examples, methine carbon (j) derived from head-to-tailchain structure of two styrene units was observed in the range of from42.3 to 43.6 ppm, and methine carbon (n) derived from head-to-tail chainstructure of 3 or more styrene units was observed in the range of from40.4 to 41.0 ppm.

Further, the aromatic vinyl compound-ethylene copolymer of the presentinvention is a copolymer having a high random property (low alternatingproperty), the λ value of which satisfies the formula (i^(Δ)).

Example 33 Preparation of styrene-1-octene copolymer

Rac-dimethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconium dichlorideprepared by Preparation D of the above transition metal catalystcomponent was used as a catalyst, and polymerization was carried outunder the following conditions.

The polymerization was carried out by using an autoclave of 10 equippedwith a stirrer and a jacket for heating and cooling.

4,400 ml of dehydrated toluene and 400 ml of 1-octene were chargedtherein, and the resultant mixture was heat-stirred at an innertemperature of 70° C. The reaction system was purged by bubbling about100 l of nitrogen, and 8.4 mmol of triisobutyl aluminum and 8.4 mmol (interms of Al) of methyl alumoxane (MMAO-3A manufactured by TOSOH AKZOCo.) were added thereto. The content of the autoclave was substituted byimmediately introducing ethylene, and atter stably fixing to a pressureof 1.1 MPa (10 kg/cm²G, atmospheric pressure), about 50 ml of toluenesolution having 1.3 μmol ofrac-dimethylmethylenebis(3-cyclopenta[c]phenanthryl)zirconium dichloride(catalyst obtained in Preparation D of the above transition metalcatalyst component) and 0.84 mmol of triisobutyl aluminum dissolved wasadded to the autoclave from a catalyst tank equipped above theautoclave. By maintaining the internal temperature of 70° C. and thepressure of 1.1 MPa, polymerization was carried out for 0.5 hour. Afterpolymerization, the polymerization liquid thus obtained was graduallyadded in a small amount into an excess amount of methanol vigorouslystirred to precipitate a polymer. Under a reduced pressure, the reactionproduct was dried at 60° C. until no weight change was observed, therebyobtaining 760 g of a polymer. Catalyst activity for 1 hour was 1,170t/mol catalyst.

The polymer thus obtained had an octene content of 9.5 mol % by 1H-NMRmeasurement, a weight average molecular weight (Mw) of 87,000 by GPCmeasurement and a molecular weight distribution (Mw/Mn) of 2.3, and alsohad a melting point of 90° C and a glass transition point of −52° C. byDSC measurement.

What is claimed is:
 1. A method for producing a polymer selected fromthe group consisting of an aromatic vinyl compound-olefin copolymer, anaromatic vinyl compound polymer, an olefin polymer and an olefincopolymer, comprising polymerizing in the presence of a polymerizationcatalyst comprising a transition metal compound and a cocatalyst,wherein the transition metal compound has the following formula (1′):

wherein A′ is an unsubstituted or substituted cyclopentaphenianthrylgroup of the following formula K-2′ or K-3′:

wherein in the above formulas K-2′ and K-3′, each of R1 and R2 ishydrogen, a C₁₋₂₀ alkyl group, a C₆₋₁₀ aryl group, a C₇₋₂₀ alkylarylgroup, a halogen atom, OSiR₃, SiR₃ or PR₂, (wherein each R is a C₁₋₁₀hydrocarbon group), provided that a plurality of R1 and a plurality ofR2 may be the same or different, respectively, and each pair of adjacentR1 and adjacent R2 may together, with the atoms joining them, form a 5-to 8-member aromatic or aliphatic ring, B′ is an unsubstituted orsubstituted cyclopentaphenanthryl group of the same chemical formula asA′, an unsubstituted or substituted benzindenyl group of the followingformula K-4′, K-5′ or K-6′, or an unsubstituted or substitutedcyclopentadienyl group, an unsubstituted or substituted indenyl group oran unsubstituted or substituted fluorenyl group, of the followingformula K-7′, K-8′ or K-9′:

 wherein in the above formulas K-4′, K-5′ and K-6′ each of R3, R4 and R5is hydrogen, a C₁₋₂₀ alkyl group, a C₆₋₁₀ aryl group, a C₇₋₂₀ alkylarylgroup, a halogen atom, OSiR₃, SiR₃ or PR₂ (wherein each R is a C₁₋₁₀hydrocarbon group), provided that a plurality of R3, a plurality of R4and a plurality of R5 may be the same or different, respectively, andeach pair of adjacent R3, adjacent R4 and adjacent R5 may together, withthe atoms joining them, form a 5- to 8-member aromatic or aliphaticring, except for forming an unsubstituted cyclopentaphenanthyrene group,wherein in the above formulas K-7′, K-8′ and K-9′ each of R6, R7 and R8is hydrogen, a C₁₋₂₀ alkyl group, a C₆₋₁₀ aryl group, a C₇₋₂₀ alkylarylgroup, a halogen atom, OSiR₃, SiR₃ or PR₂ (wherein each R is a C₁₋₁₀hydrocarbon group), provided that a plurality of R6, a plurality of R7and a plurality of R8 may be the same or different, respectively, whenboth A′ and B′ are unsubstituted or substituted cyclopentaphenanthrylgroups, they may the same or different, Y′ is a methylene group or aboron atom, which has bonds to A′ and B′ and which has, as substituents,hydrogen or a C₁₋₁₅ hydrocarbon group, wherein the substituents may bethe same or different from each other, or Y′ may have, together with thesubstituents, a cyclic structure including a cyclohexylidene group or acyclopentylidene group, X is hydrogen, a halogen atom, a C₁₋₁₅ alkylgroup, a C₆₋₁₀ aryl group, a C₈-C₁₂ alkylaryl group, a silyl grouphaving C₁-C₄ hydrocarbon substituent, C₁-C₁₀ alkoxy group or adialkylamide group having a C₁-C₆ alkyl substituent, and M is zirconium,hafnium or titanium.
 2. The method of claim 1, wherein the polymer is anaromatic vinyl compound-olefin copolymer.
 3. The method of claim 1,wherein the polymer is an aromatic vinyl compound polymer.
 4. The methodof claim 1, wherein the polymer is an olefin polymer or an olefincopolymer.